#include <fstream>

using namespace std;
ifstream fin("cmmdc.in");
ofstream fout("cmmdc.out");
int main()
{
unsigned int a,b;
fin>>a>>b;
while(a!=b)
{if(a>b)
a=a-b;
else
b=b-a;
}
if(a==1)
fout<<"0";
    else
fout<<a;
    return 0;
}