#include<stdio.h>
int gcd(int a,int b){
    if (b==0)
    return a;
    else 
    return gcd(b,a%b);
    
}
int main(){
    int a,b;
    scanf("%d",&a);
    scanf("%d",&a);
    scanf("%d",&b);
    if(a <=0||b<=0)
    printf("Invalid input");
    else{
        int result=gcd(a,b);
        if(result<0)
        result=-result;
        printf("%\n",result);
    }
    return 0;
    
}