#include <stdio.h>

int main()
{
    FILE *in=fopen("cmmdc.in","r");
    long a,b,aux;
    fscanf(in,"%ld",&a);
    fscanf(in,"%ld",&b);
    fclose(in);
    while(b)
    {
        aux=b;
        b=a%b;
        a=aux;
    }
    FILE *out=fopen("cmmdc.out","w");
    if (a==1)
        fprintf(out,"0");
    else
        fprintf(out,"%ld",a);
    fclose(out);
    return 0;
}