#include <iostream>
using namespace std;

void cmmdc (int a, int b)
{if (a!=b)
{if (a>b)
cmmdc (a-b, b);
else
cmmdc (a, b-a);
}
cout<<b;
}
int main ()
{int a,b;
    cin>>a>>b;
cmmdc (a,b);
return 0;
}