infoarena informatica de performanta

#include <stdio.h>

int main(){

   freopen("cmmdc.in", "r", stdin);
   freopen("cmmdc.out", "w", stdout);

   unsigned a, b, r;

   scanf("%u\n%u", &a, &b);

   r = a % b;

   while(r > 0){
      a = b;
      b = r;
      r = a % b;
      if(r == 1){
         printf("0\n");
         break;
      }
   }
   if(r == 0){
      if(a == b){
         printf("0\n");
      }
      else{
         printf("%u\n", b);
      }
   }

   return 0;
}

Iau doar 90 puncte, de ce, ma poate ajuta cineva?