diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0995a96..41c325f 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -46,10 +46,10 @@ repos:
     hooks:
       - id: pyupgrade
         args: [--py37-plus]
-  # - repo: https://github.com/pre-commit/mirrors-autopep8
-  #   rev: v2.0.0
-  #   hooks:
-  #     - id: autopep8
+  - repo: https://github.com/pre-commit/mirrors-autopep8
+    rev: v2.0.0
+    hooks:
+      - id: autopep8
   # - repo: https://github.com/Zac-HD/shed
   #   rev: 0.10.7
   #   hooks:
diff --git a/README.md b/README.md
index 3aa9486..6ecd9dc 100644
--- a/README.md
+++ b/README.md
@@ -13,8 +13,8 @@
 | 03 | [puzzle][201503p]</br>[✓][201503] |  |  |  |  |  |  |  |
 | 04 | [puzzle][201504p]</br>[✓][201504] |  |  |  |  |  |  |  |
 | 05 | [puzzle][201505p]</br>[✓][201505] |  |  |  |  |  |  |  |
-|    |      |  |  |  |  |  |  |  |
-|    |      |  |  |  |  |  |  |  |
+| 06 | [puzzle][201506p]</br>[✓][201506] |  |  |  |  |  |  |  |
+| 07 | [puzzle][201507p]</br>[✓][201507] |  |  |  |  |  |  |  |
 | 08 | [puzzle][201508p]</br>[✓][201508] |  |  |  |  |  |  |  |
 
 [201501]: https://github.com/Stegallo/adventofcode/blob/master/y_2015/day1.py
@@ -31,8 +31,6 @@
 [201506p]: https://adventofcode.com/2015/day/6
 [201507]: https://github.com/Stegallo/adventofcode/blob/master/y_2015/day7.py
 [201507p]: https://adventofcode.com/2015/day/7
-
-
 [201508]: https://github.com/Stegallo/adventofcode/blob/master/y_2015/day8.py
 [201508p]: https://adventofcode.com/2015/day/8
 
diff --git a/common/utilities.py b/common/utilities.py
new file mode 100644
index 0000000..0831531
--- /dev/null
+++ b/common/utilities.py
@@ -0,0 +1,18 @@
+def bitand(x: int, y: int) -> int:
+    return x & y
+
+
+def bitor(x: int, y: int) -> int:
+    return x | y
+
+
+def lshift(x: int, y: int) -> int:
+    return x << y
+
+
+def rshift(x: int, y: int) -> int:
+    return x >> y
+
+
+def bitnot(x: int) -> int:
+    return x ^ 65535
diff --git a/requirements/test.txt b/requirements/test.txt
index 2c24905..c5a0900 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -3,3 +3,4 @@ flake8
 isort
 pre-commit
 pytest
+pytest-cov
diff --git a/tests/common/test_utilites.py b/tests/common/test_utilites.py
new file mode 100644
index 0000000..5c01f67
--- /dev/null
+++ b/tests/common/test_utilites.py
@@ -0,0 +1,9 @@
+from common.utilities import bitand, bitor, lshift, rshift, bitnot
+
+
+def test_bit_ops():
+    assert bitand(1, 2) == 0
+    assert bitor(1, 2) == 3
+    assert lshift(1, 2) == 4
+    assert rshift(1, 2) == 0
+    assert bitnot(1) == 65534
diff --git a/tests/y_2015/test_2015_day7.py b/tests/y_2015/test_2015_day7.py
index 4b722d5..704dfc0 100644
--- a/tests/y_2015/test_2015_day7.py
+++ b/tests/y_2015/test_2015_day7.py
@@ -2,7 +2,7 @@
 
 from unittest.mock import mock_open, patch
 
-from y_2015.day7 import Day
+from y_2015.day7 import Day, Element
 
 with patch(
     "builtins.open",
@@ -28,37 +28,16 @@ def test_calculate_1():
 def test_calculate_2():
     assert day._calculate_2() == 123
 
-# def test_ingress_resolve():
-#     ingress = Ingress('123')
-#     assert ingress.resolve({}) == Ingress('123')
-#
-#     ingress = Ingress('a')
-#     assert ingress.resolve({'a': Ingress('1')}) == Ingress('1')
-#
-#     ingress = Ingress('NOT 1')
-#     assert ingress.resolve({}) == Ingress('65534')
-#
-#     ingress = Ingress('NOT a')
-#     assert ingress.resolve({'a': Ingress('1')}) == Ingress('65534')
-#
-#     ingress = Ingress('x AND y')
-#     assert ingress.resolve({'x': Ingress('123'), 'y': Ingress('456')}) ==
-# Ingress('72')
-#
-#     ingress = Ingress('x OR y')
-#     assert ingress.resolve({'x': Ingress('123'), 'y': Ingress('456')}) ==
-# Ingress('507')
-#
-#     ingress = Ingress('x LSHIFT 2')
-#     assert ingress.resolve({'x': Ingress('123')}) == Ingress('492')
-#
-#     ingress = Ingress('y RSHIFT 2')
-#     assert ingress.resolve({'y': Ingress('456')}) == Ingress('114')
-#
-#     ingress = Ingress('NOT a')
-#     assert ingress.resolve({'a': Ingress('NOT b'), 'b': Ingress('1')}) ==
-# Ingress('1')
-#
-#     ingress = Ingress('NOT a')
-#     assert ingress.resolve({'a': Ingress('NOT b'), 'b': Ingress('NOT c'),
-# 'c': Ingress('NOT d'), 'd':Ingress('x'), 'x': Ingress('1  ')}) == Ingress('1')
+
+def test_Element_resolve():
+    element = Element('123')
+    assert element.resolve({}) == 123
+
+    element = Element('a')
+    assert element.resolve({'a': Element('1')}) == 1
+
+    element = Element('NOT 1')
+    assert element.resolve({}) == 65534
+
+    element = Element('a')
+    assert element.resolve({'a': Element('b AND b'), 'b': Element('1')}) == 1
diff --git a/y_2015/day7.py b/y_2015/day7.py
index ddc03e3..b4dd0f7 100644
--- a/y_2015/day7.py
+++ b/y_2015/day7.py
@@ -5,24 +5,7 @@
 from common.aoc import AoCDay
 
 
-def bitand(x: int, y: int) -> int:
-    return x & y
-
-
-def bitor(x: int, y: int) -> int:
-    return x | y
-
-
-def lshift(x: int, y: int) -> int:
-    return x << y
-
-
-def rshift(x: int, y: int) -> int:
-    return x >> y
-
-
-def bitnot(x: int) -> int:
-    return x ^ 65535
+from common.utilities import bitand, bitor, lshift, rshift, bitnot
 
 
 OPERATORS: Dict[str, Any] = {
diff --git a/y_2015/day9.py b/y_2015/day9.py
new file mode 100644
index 0000000..2a6ff1b
--- /dev/null
+++ b/y_2015/day9.py
@@ -0,0 +1,21 @@
+from common.aoc import AoCDay
+
+
+class Day(AoCDay):
+    def __init__(self, test=0):
+        super().__init__(__name__, test)
+
+    def _preprocess_input(self):
+        # self.__input_data = [[int(i) for i in chunk] for chunk in self._input_data]
+        print(f"{self._input_data=}")
+        self.__input_data = self._input_data[0]
+
+    def _calculate_1(self):
+        x = self.__input_data
+        print(f"{x=}")
+        return 0
+
+    def _calculate_2(self):
+        x = self.__input_data
+        print(f"{x=}")
+        return 0