#include <iostream>
using namespace std;
void main()
{int a,b,g,h,yu;
cout<<"输入两个数,可以计算出最大公约数";
cin>>a>>b;
if (a>b)
{g=a;h=b;}
else if (a<b)
{g=b;h=a;}
else {h=a;goto Loop;}
yu=g%h;
if (yu=0)
{goto Loop;}
else do {
g=h;
h=yu;
yu=g%h;
} while(yu!=0);
Loop:cout<<"是"<<h<<endl;
}