#include<stdio.h>
void main()
{
   int x,y,n;
   scanf("%d,%d",&x,&y);
   if(x>y) n=y;
   else n=x;
   for(;n>1;n--)
      {
         if(x%n==0&&y%n==0)
            {
               printf("最大公约数=%d\n",n);
               break;
            }
       }

getch();
}

不用麻烦高手们了~~~原来是教材上的答案错了~~~