diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/factorial.py b/factorial.py
index 3569741..7d5460a 100755
--- a/factorial.py
+++ b/factorial.py
@@ -7,17 +7,22 @@
 
 
 def factorial(n):
-    # TODO Define your logic for factorial here
-    return # TODO!
+    # Define your logic for factorial here
+    if n == 1 or n == 0:
+        return 1
+    else:
+        return n * factorial(n-1)
+
 
 def test_factorial():
+    # Tests the function with value 1
     assert factorial(1) == 1
-    # TODO: add more
+    assert factorial(0) == 1
+
 
 if __name__ == '__main__':
     # This is a way to determine either file was "executed", so if it was
-    # imported (by e.g. pytest) as a library, we should not run code
-    # below
-    nconditions = raw_input("Please enter number of conditions: ")
-    norders = factorial(nconditions)
-    print("Number of possible trial orders: " + str(norders)
+    # imported as a library, we should not run code below
+    conditions = int(input("Please enter number of conditions: "))
+    orders = factorial(conditions)
+    print("Number of possible trial orders: " + str(orders))