#include <iostream>
using namespace std;
//自定义函数的原型(即函数声明)
int gcd(int,int);
int main()
{
int a,b,g;
cin>>a>>b;
g=gcd(a,b);
cout<<g<<endl;
return 0;
}
int gcd(int x,int y)
{ int z;
while (x!=0)
{
z=y%x;
y=x;
x=z;
}
return y;
}