diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..3b8b06b
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,22 @@
+# This is a basic workflow to help you get started with Actions
+
+name: CI
+
+on: push
+
+jobs:
+  code_quality:
+    runs-on: ubuntu-latest
+    name: Checks with black, isort and possibly run tests
+    container: python:3.9
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Run script
+        run: |
+          pip install flake8 isort pytest
+          ls -la
+          flake8 .
+          isort --check .
+          py.test tests
diff --git a/homework1/.gitignore b/homework1/.gitignore
deleted file mode 100644
index 1ceb2fd..0000000
--- a/homework1/.gitignore
+++ /dev/null
@@ -1,132 +0,0 @@
-# Byte-compiled / optimized / DLL files
-__pycache__/
-*.py[cod]
-*$py.class
-
-# C extensions
-*.so
-
-# Distribution / packaging
-.Python
-build/
-develop-eggs/
-dist/
-downloads/
-eggs/
-.eggs/
-lib/
-lib64/
-parts/
-sdist/
-var/
-wheels/
-pip-wheel-metadata/
-share/python-wheels/
-*.egg-info/
-.installed.cfg
-*.egg
-MANIFEST
-
-# PyInstaller
-#  Usually these files are written by a python script from a template
-#  before PyInstaller builds the exe, so as to inject date/other infos into it.
-*.manifest
-*.spec
-
-# Installer logs
-pip-log.txt
-pip-delete-this-directory.txt
-
-# Unit test / coverage reports
-htmlcov/
-.tox/
-.nox/
-.coverage
-.coverage.*
-.cache
-nosetests.xml
-coverage.xml
-*.cover
-*.py,cover
-.hypothesis/
-.pytest_cache/
-
-# Translations
-*.mo
-*.pot
-
-# Django stuff:
-*.log
-local_settings.py
-db.sqlite3
-db.sqlite3-journal
-
-# Flask stuff:
-instance/
-.webassets-cache
-
-# Scrapy stuff:
-.scrapy
-
-# Sphinx documentation
-docs/_build/
-
-# PyBuilder
-target/
-
-# Jupyter Notebook
-.ipynb_checkpoints
-
-# IPython
-profile_default/
-ipython_config.py
-
-# pyenv
-.python-version
-
-# pipenv
-#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
-#   However, in case of collaboration, if having platform-specific dependencies or dependencies
-#   having no cross-platform support, pipenv may install dependencies that don't work, or not
-#   install all needed dependencies.
-#Pipfile.lock
-
-# PEP 582; used by e.g. github.com/David-OConnor/pyflow
-__pypackages__/
-
-# Celery stuff
-celerybeat-schedule
-celerybeat.pid
-
-# SageMath parsed files
-*.sage.py
-
-# Environments
-.env
-.venv
-env/
-venv/
-ENV/
-env.bak/
-venv.bak/
-
-# Spyder project settings
-.spyderproject
-.spyproject
-
-# Rope project settings
-.ropeproject
-
-# mkdocs documentation
-/site
-
-# mypy
-.mypy_cache/
-.dmypy.json
-dmypy.json
-
-# Pyre type checker
-.pyre/
-
-# ide
-.idea/
diff --git a/homework1/requirements.txt b/homework1/requirements.txt
deleted file mode 100644
index 769dce2..0000000
--- a/homework1/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-pytest
-pytest-sugar
\ No newline at end of file
diff --git a/homework1/sample_project/calculator/calc.py b/homework1/sample_project/calculator/calc.py
deleted file mode 100644
index f214d8f..0000000
--- a/homework1/sample_project/calculator/calc.py
+++ /dev/null
@@ -1,2 +0,0 @@
-def check_power_of_2(a: int) -> bool:
-    return bool(a & (a - 1) == 0 and (a != 0))
diff --git a/homework1/sample_project/requirements.txt b/homework1/sample_project/requirements.txt
deleted file mode 100644
index 1bf5204..0000000
--- a/homework1/sample_project/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-pytest
-pytest-sugar
diff --git a/homework1/sample_project/tests/__init__.py b/homework1/sample_project/tests/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/homework1/sample_project/tests/test_calculator.py b/homework1/sample_project/tests/test_calculator.py
deleted file mode 100644
index 1cfe600..0000000
--- a/homework1/sample_project/tests/test_calculator.py
+++ /dev/null
@@ -1,15 +0,0 @@
-import pytest
-
-from sample_project.calculator.calc import check_power_of_2
-
-def test_positive_case():
-    """Testing that actual powers of 2 give True"""
-    assert check_power_of_2(65536)
-    assert check_power_of_2(8)
-    assert check_power_of_2(256)
-    assert check_power_of_2(2048)
-def test_negative_case():
-    """Testing that non-powers of 2 give False"""
-    assert not check_power_of_2(12)
-    assert not check_power_of_2(0)
-    assert not check_power_of_2(-16)
diff --git a/homework1/tasks/__init__.py b/homework1/tasks/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/homework1/tasks/task02.py b/homework1/tasks/task02.py
deleted file mode 100644
index 3f71dc6..0000000
--- a/homework1/tasks/task02.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from typing import Sequence
-
-
-def check_fibonacci(data: Sequence[int]) -> bool:
-    for element in range(2, len(data)):
-        if data[element] == data[element - 1] + data[element - 2]:
-            continue
-        else:
-            return False
-    return True
-
diff --git a/homework1/tasks/task03.py b/homework1/tasks/task03.py
deleted file mode 100644
index fd0e17f..0000000
--- a/homework1/tasks/task03.py
+++ /dev/null
@@ -1,17 +0,0 @@
-from typing import Tuple
-
-
-def find_maximum_and_minimum(file_name: str) -> Tuple[int, int]:
-    max = 1
-    min = 1
-    with open(file_name) as fi:
-        for line in fi:
-            if int(line) > max:
-                max = int(line)
-            elif int(line) < min:
-                min = int(line)
-            else:
-                continue
-        a = min, max
-        print(a)
-        return a
diff --git a/homework1/tasks/task04.py b/homework1/tasks/task04.py
deleted file mode 100644
index 4369551..0000000
--- a/homework1/tasks/task04.py
+++ /dev/null
@@ -1,10 +0,0 @@
-from typing import List
-
-def check_sum_of_four(a: List[int], b: List[int], c: List[int], d: List[int]) -> int:
-    counter = 0
-    for i in range (0, len(a)):
-        if a[i] + b[i] + c[i] + d[i] == 0:
-            counter += 1
-        else:
-            continue
-    return counter
\ No newline at end of file
diff --git a/homework1/tasks/task05.py b/homework1/tasks/task05.py
deleted file mode 100644
index a02440a..0000000
--- a/homework1/tasks/task05.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from typing import List
-
-
-def find_maximal_subarray_sum(nums: List[int], k: int) -> int:
-    summ = 0
-    current_sum = 0
-    for num in nums:
-        current_sum = sum(nums[num:k+num])
-        if current_sum > summ:
-            summ = current_sum
-    return summ
\ No newline at end of file
diff --git a/homework1/tests/__init__.py b/homework1/tests/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/homework1/tests/some_file.txt b/homework1/tests/some_file.txt
deleted file mode 100644
index 1341a1e..0000000
--- a/homework1/tests/some_file.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-0
-1
-2
-3
-4
-5
-6
-16
-18
-22222222
\ No newline at end of file
diff --git a/homework1/tests/tests.py b/homework1/tests/tests.py
deleted file mode 100644
index d799d48..0000000
--- a/homework1/tests/tests.py
+++ /dev/null
@@ -1,49 +0,0 @@
-import pytest
-
-from tasks.task02 import check_fibonacci
-from tasks.task03 import find_maximum_and_minimum
-from tasks.task04 import check_sum_of_four
-from tasks.task05 import find_maximal_subarray_sum
-
-
-def test_task_02():
-    check1 = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
-    check2 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
-    check3 = [25, 26, 1, 2, 3, 5, 8, 13, 21, 34, 55]
-
-    assert check_fibonacci(check1)
-    assert check_fibonacci(check2) is False
-    assert check_fibonacci(check3) is False
-
-
-def test_task_03():
-    assert find_maximum_and_minimum("some_file.txt")
-
-
-def test_task_04():
-    a = [2, 4, 6, 8]
-    b = [0, -4, 6, 8]
-    c = [-2, 0, -12, 8]
-    d = [0, 0, 0, -24]
-
-    a1 = [0, 5, 5, 5, 5, 5, 5, 5, 5, 5]
-    b1 = [0, 6, -5, 5, 7, 2, 3, 6, 2, 3]
-    c1 = [0, 2, 3, 4, 5, 6, 7, 1, 6, 1]
-    d1 = [0, 3, -3, 4, 6, 7, 8, 9, 1, 3]
-
-    # check
-    assert (check_sum_of_four(a, b, c, d),
-            check_sum_of_four(a1, b1, c1, d1), check_sum_of_four(b, b1, c1, d), check_sum_of_four(a, b1, c1, d))
-
-
-def test_task_05():
-    nums = [1, 3, -1, -3, 5, 3, 6, 7]
-    k = 3
-
-    nums_1 = [0, 2, -2, 4, 6, 7, 8, 9, 9, 12, 12, -4, -5, -22, -30]
-    k_1 = 2
-
-    nums_2 = [0, 1, 2, 3]
-    k_2 = 10
-    assert (find_maximal_subarray_sum(nums, k), find_maximal_subarray_sum(nums_1, k_1),
-            find_maximal_subarray_sum(nums_2, k_2))
diff --git a/homework1/__init__.py b/homework3/__init__.py
similarity index 100%
rename from homework1/__init__.py
rename to homework3/__init__.py
diff --git a/homework3/task01.py b/homework3/task01.py
new file mode 100644
index 0000000..8275b59
--- /dev/null
+++ b/homework3/task01.py
@@ -0,0 +1,49 @@
+"""
+In previous homework task 4, you wrote a cache function that remembers other
+function output value. Modify it to be a parametrized decorator,
+so that the following code:
+
+@cache(times=3)
+def some_function():
+    pass
+Would give out cached value up to times number only. Example:
+
+@cache(times=2)
+def f():
+    return input('? ')   # careful with input() in python2,
+    use raw_input() instead
+f()
+? 1
+'1'
+f()     # will remember previous value
+'1'
+f()     # but use it up to two times only
+'1'
+f()
+? 2
+'2'
+"""
+
+import functools
+
+
+def cache(times):
+    def wrapped_cache(func):
+        cache_dict = {}
+        counter = times
+
+        @functools.wraps(func)
+        def wrapped_func(*args, **kwargs):
+            nonlocal counter
+            if counter > 0 and args in cache_dict:
+                counter -= 1
+                return cache_dict[args]
+            else:
+                values_to_cache = func(*args, **kwargs)
+                cache_dict[args] = values_to_cache
+                counter = times - 1
+                return values_to_cache
+
+        return wrapped_func
+
+    return wrapped_cache
diff --git a/homework3/task02.py b/homework3/task02.py
new file mode 100644
index 0000000..91b4465
--- /dev/null
+++ b/homework3/task02.py
@@ -0,0 +1,49 @@
+"""
+Here's a not very efficient calculation function that calculates
+something important:
+
+import time
+import struct
+import random
+import hashlib
+
+def slow_calculate(value):
+    """"""Some weird voodoo magic calculations""""""
+    time.sleep(random.randint(1,3))
+    data = hashlib.md5(str(value).encode()).digest()
+    return sum(struct.unpack('<' + 'B' * len(data), data))
+
+Calculate total sum of slow_calculate() of all numbers
+starting from 0 to 500.
+Calculation time should not take more than a minute.
+Use functional capabilities of multiprocessing module.
+You are not allowed to modify slow_calculate function.
+"""
+
+import hashlib
+import random
+import struct
+import time
+from multiprocessing import Pool, freeze_support
+
+
+def slow_calculate(value):
+    """Some weird voodoo magic calculations"""
+    time.sleep(random.randint(1, 3))
+    data = hashlib.md5(str(value).encode()).digest()
+    return sum(struct.unpack('<' + 'B' * len(data), data))
+
+
+def timing():
+    start_time = time.time()
+    return lambda x: print("[{:.2f}s] {}".format(time.time() - start_time, x))
+
+
+def pool_calculation(last_value, processors):
+    loop_range = range(0, last_value)
+    with Pool(processors) as pool:
+        return sum(pool.map(slow_calculate, loop_range))
+
+
+if __name__ == '__main__':
+    freeze_support()
diff --git a/homework3/task03.py b/homework3/task03.py
new file mode 100644
index 0000000..dc56d00
--- /dev/null
+++ b/homework3/task03.py
@@ -0,0 +1,58 @@
+# I decided to write a code that generates data filtering
+# object from a list of keyword parameters:
+
+class Filter:
+    """
+        Helper filter class. Accepts a list of single-argument
+        functions that return True if object in list conforms to some criteria
+    """
+
+    def __init__(self, functions):
+        self.functions = functions
+
+    def apply(self, data):
+        return [
+            item for item in data
+            if all(i(item) for i in self.functions)
+        ]
+
+
+# example of usage:
+# positive_even = Filter(lamba a: a % 2 == 0, lambda a: a > 0,
+# lambda a: isinstance(int, a)))
+# positive_even.apply(range(100)) should return only even numbers from 0 to 99
+
+
+def make_filter(**keywords):
+    """
+        Generate filter object for specified keywords
+    """
+    filter_funcs = []
+    for key, value in keywords.items():
+        def keyword_filter_func(sub_value):
+            return sub_value.get(key) == value
+
+        filter_funcs.append(keyword_filter_func)
+    return Filter(filter_funcs)
+
+
+sample_data = [
+    {
+        "name": "Bill",
+        "last_name": "Gilbert",
+        "occupation": "was here",
+        "type": "person",
+    },
+    {
+        "is_dead": True,
+        "kind": "parrot",
+        "type": "bird",
+        "name": "polly"
+    }
+]
+
+# make_filter(name='polly', type='bird').apply(sample_data)
+# should return only second entry from the list
+
+# There are multiple bugs in this code.
+# Find them all and write tests for faulty cases.
diff --git a/homework3/task04.py b/homework3/task04.py
new file mode 100644
index 0000000..739f239
--- /dev/null
+++ b/homework3/task04.py
@@ -0,0 +1,23 @@
+"""
+Armstrong number is a number that is the sum of its
+own digits each raised to the power of the number of digits.
+https://en.wikipedia.org/wiki/Narcissistic_number
+Examples:
+- 9 is an Armstrong number, 9 = 9^1 = 9
+- 10 is not: 10 != 1^2 + 0^2 = 1
+- 153 is : 153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153
+Write a function that detects if a number is
+Armstrong number in functionaly style:
+ - use map or other utilities from functools library,
+ - use anonymous functions (or use function as argument)
+ - do not use loops, preferably using list comprehensions
+### Example function signature and call
+"""
+
+
+def is_armstrong(number: int) -> bool:
+    end_sum = 0
+    power = len(str(number))
+    for i in str(number):
+        end_sum += pow(int(i), int(power))
+    return number == end_sum
diff --git a/homework1/sample_project/__init__.py b/tests/__init__.py
similarity index 100%
rename from homework1/sample_project/__init__.py
rename to tests/__init__.py
diff --git a/homework1/sample_project/calculator/__init__.py b/tests/homework3/__init__.py
similarity index 100%
rename from homework1/sample_project/calculator/__init__.py
rename to tests/homework3/__init__.py
diff --git a/tests/homework3/test_task01.py b/tests/homework3/test_task01.py
new file mode 100644
index 0000000..d25f8b3
--- /dev/null
+++ b/tests/homework3/test_task01.py
@@ -0,0 +1,18 @@
+from homework3.task01 import cache
+
+counter = 0
+
+
+def test_cache_decorator():
+    @cache(times=2)
+    def f(a, b):
+        global counter
+        counter += 1
+        return a + b
+
+    assert f(1, 2) == 3
+    assert counter == 1
+    assert f(1, 2) == 3
+    assert counter == 1
+    assert f(1, 2) == 3
+    assert counter == 2
diff --git a/tests/homework3/test_task02.py b/tests/homework3/test_task02.py
new file mode 100644
index 0000000..676233f
--- /dev/null
+++ b/tests/homework3/test_task02.py
@@ -0,0 +1,23 @@
+import time
+
+from homework3.task02 import pool_calculation, slow_calculate
+
+
+def slow_calculation_loop(last_value):
+    loop_range = range(0, last_value)
+    return sum(slow_calculate(i) for i in loop_range)
+
+
+def test_result_of_slow_calculation():
+    assert pool_calculation(500, 30) == 1024259
+
+
+def test_time_of_slow_calculation():
+    start_time = time.time()
+    pool_calculation(500, 30)
+    end_time = time.time() - start_time
+    assert end_time < 60
+
+
+def test_equal_results_from_both_func():
+    assert pool_calculation(5, 30) == slow_calculation_loop(5)
diff --git a/tests/homework3/test_task03.py b/tests/homework3/test_task03.py
new file mode 100644
index 0000000..fad4fcf
--- /dev/null
+++ b/tests/homework3/test_task03.py
@@ -0,0 +1,7 @@
+from homework3.task03 import make_filter, sample_data
+
+
+def test_main_result():
+    result = [{'is_dead': True, 'kind': 'parrot',
+               'type': 'bird', 'name': 'polly'}]
+    assert make_filter(name='polly', type='bird').apply(sample_data) == result
diff --git a/tests/homework3/test_task04.py b/tests/homework3/test_task04.py
new file mode 100644
index 0000000..8017592
--- /dev/null
+++ b/tests/homework3/test_task04.py
@@ -0,0 +1,17 @@
+from homework3.task04 import is_armstrong
+
+
+def test_positive_armstrong_list():
+    armstrong_numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407,
+                         1634, 8208, 9474, 54748, 92727, 93084, 548834,
+                         1741725, 4210818, 9800817, 146511208, 472335975,
+                         534494836, 912985153, 4679307774]
+
+    for i in armstrong_numbers:
+        assert is_armstrong(i)
+
+
+def test_negative_armstrong():
+    just_numbers = [10, 11, 12, 124, 555, 666]
+    for i in just_numbers:
+        assert not is_armstrong(i)