diff --git a/function_a.py b/function_a.py
index 0bc43c29..3b66319e 100644
--- a/function_a.py
+++ b/function_a.py
@@ -1,7 +1,21 @@
 def most_common_value(number_list):
     """ returns the most common element of the list
     """
-    pass
+    frequency_index = {}
+    max_frequency = -1
+    most_common_value = None
+    for num in number_list:
+        if frequency_index.get(num):
+            frequency_index[num] += 1
+        else:
+            frequency_index[num] = 1
+
+        if max_frequency < frequency_index[num]:
+            max_frequency = frequency_index[num]
+            most_common_value = num
+
+    return most_common_value
+
 
 
 if __name__ == "__main__":
diff --git a/function_b.py b/function_b.py
index e888b354..215ca8c2 100644
--- a/function_b.py
+++ b/function_b.py
@@ -7,7 +7,17 @@ def silly_sum():
         the user enters 0, or
         the sum reaches or exceeds 1000
     """
-    pass
+    num = int(input('Please enter a number => '))
+    sum = 0
+
+    while num != 0:
+        sum += num
+        if sum >= 1000:
+            break
+
+        num = int(input('Please enter a number => '))
+
+    return sum
 
 
 if __name__ == "__main__":
diff --git a/function_c.py b/function_c.py
index deb1023c..5efcf2b4 100644
--- a/function_c.py
+++ b/function_c.py
@@ -3,8 +3,8 @@ def merge_lists(list_a, list_b):
         a combination of list_a and list_b
         without any duplicate elements.
     """
-    pass
-
+    return list(set(list_a) | set(list_b))
 
 if __name__ == "__main__":
     print(merge_lists([1, 1, 2, 3], [3, 4, 5]))
+