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