#include <stdio.h>
main()
{ int t,r,u,v;
printf("please input two numbers :\n");
scanf("%d,%d",u,v);
if (v>u)
{t=u;u=v;v=t;}
while((r=u%v)!=0)
{ r=u%v;
u=v;v=r;}
printf("%d",v);
}

八楼 厉害