diff --git a/linear_program.py b/linear_program.py
index 9f9f6ab..d296935 100644
--- a/linear_program.py
+++ b/linear_program.py
@@ -12,7 +12,7 @@
 
 # simple matrix sum function
 def sumMatrix(matrix):
-    return sum(sum(row) for row in matrix)
+    return int(sum(sum(row) for row in matrix))
 
 
 # solve linear system