#include <iostream>
#include <cstdio>
FILE *fin=fopen("cmmdc.in", "r"), *fout=fopen("cmmdc.out", "w");
using namespace std;
int x, y, r;
int main()
{
    fscanf(fin, "%d%d", &x, &y);
    if(x==1||y==1)
        fprintf(fout, "1");
    else
    r=x%y;
    while(r)
    {
        x=y;
        y=r;
        r=x%y;
    }
    if(y!=1)
        fprintf(fout, "%d\n", y);
    else fprintf(fout, "0");
    return 0;
}