#include <cstdio>

using namespace std;

int x,y,n;

int cmmdc(int x,int y)
{
    if(y ==0)
        return x;
    return cmmdc(y,x%y);
}

int main()
{

    freopen("cmmdc.in","r",stdin);
    freopen("cmmdc.out","w",stdout);
    scanf("%d %d",&x,&y);
    if(cmmdc(x,y) == 1)
        printf("0");
    else
        printf("%d\n",cmmdc(x,y));

    return 0;
}