#include
int main()
{
int a,b,r,result;

printf("please input 2 integers:\n");
scanf("%d%d",&a,&b);
if(a>=b)
r=a%b;
else
{r=a;
a=b;
b=r;
r=a%b;}
while(r!=0)
{a=b;b=r;r=a%b;}

printf("result=%d",b);
}