diff --git a/captains room.py b/captains room.py
index 25e9d6d..01f3af7 100644
--- a/captains room.py	
+++ b/captains room.py	
@@ -1,3 +1,7 @@
+'''
+Source: https://www.hackerrank.com/challenges/py-the-captains-room/problem
+'''
+
 K = int(input())
 room_numbers = map(int, input().split())
 rooms = set(room_numbers)
diff --git a/kangaroo.py b/kangaroo.py
index b89d2b5..454681d 100644
--- a/kangaroo.py
+++ b/kangaroo.py
@@ -1,3 +1,7 @@
+'''
+Source: https://www.hackerrank.com/challenges/kangaroo/problem
+'''
+
 x1,v1,x2,v2 = raw_input().strip().split(' ')
 x1,v1,x2,v2 = [int(x1),int(v1),int(x2),int(v2)]
 
diff --git a/mutations.py b/mutations.py
index 44a672d..fd880e5 100644
--- a/mutations.py
+++ b/mutations.py
@@ -1,3 +1,7 @@
+'''
+Source: https://www.hackerrank.com/challenges/python-mutations/problem
+'''
+
 n=input()
 m=input().split()
 l=list(n)
diff --git a/noidea.py b/noidea.py
index 0df1db6..bbf30fa 100644
--- a/noidea.py
+++ b/noidea.py
@@ -1,3 +1,7 @@
+'''
+Source: https://www.hackerrank.com/challenges/no-idea/problem
+'''
+
 n=input()
 count=0
 a=set(input())
diff --git a/setmutation.py b/setmutation.py
index e26c0ce..285e135 100644
--- a/setmutation.py
+++ b/setmutation.py
@@ -1,3 +1,7 @@
+'''
+Source: https://www.hackerrank.com/challenges/py-set-mutations/problem
+'''
+
 n = int(input())
 count=0
 s = set(map(int, input().split()))