diff --git a/constellation.py b/constellation.py
index e4053d9..60cc5d0 100755
--- a/constellation.py
+++ b/constellation.py
@@ -6,11 +6,25 @@ class Star:
     def dist_sqr(self, star):
         return (self.x - star.x) ** 2 + (self.y - star.y) ** 2
 
+    def __repr__(self):
+        return str(self)
+
+    def __str__(self):
+        return "(" + str(self.x) + "," + str(self.y) + ")"
+
+def print_M(M):
+    for i in range(len(M)):
+        print(M[i])
+    print()
+
 def find_constellations(M, S):
     for i in range(len(S)):
         for j in range(i+1, len(S)):
             M[i][j] = Star.dist_sqr(S[i], S[j])
             M[j][i] = M[i][j]
+            #print(str(S[i]) + " - " + str(S[j]) + ": " + str(M[i][j]))
+    #print_M(M)
+    #print(S)
     c = 0
     for i in range(len(S)):
         D = {}
@@ -28,7 +42,9 @@ def find_constellations(M, S):
 
 if __name__ == "__main__":
     n = int(input())
-    M = [[None] * n] * n
+    M = []
+    for i in range(n):
+        M.append([None] * n)
     S = []
     for i in range(n):
         st = input().split()