diff --git a/src/gcd.c b/src/gcd.c
index 2792dbc..9eca57c 100644
--- a/src/gcd.c
+++ b/src/gcd.c
@@ -1,8 +1,10 @@
 #include <stdio.h>
 
-const int n = 10000;
+const int n = 1000;
 
 unsigned int Euclidean_gcd_rec(unsigned int x, unsigned int y){
+  if(x == 0) return y;
+  return Euclidean_gcd_rec(y % x, x);
 }
 
 /*