#include<stdio.h>
int main(){
    int n,m;
    scanf("%d %d",&n,&m);
    if(n<=0||m<0||n>100||m>100)
    printf("Invalid input");
    else{
        while(m!=0){
            int temp=m;
            m=n%m;
            n=temp;
        }
        printf("%d",n)
    }
    return 0;
}