#include<iostream>
using namespace std;
int Eucld(int a, int b)
{
if (a < b)
{
int t = a;
a = b;
b = t;
}
if (b == 0)
return a;
else
{
int t = b;
b = a%t;
a = t;
return Eucld(a, b);
}
}
void main()
{
int a, b;
cin >> a >> b;
cout<<Eucld(a, b)<<endl;
system("pause");
}