#include<stdio.h>

//recursive function to find GCD
int gcd(int a,int b){
    if(b==0)
    return a;
    return gcd(b,a%b);
}

int main(){
    int a,b;
    scanf("%d%d",&a,&b);
    
    if(a<=0||b<=0){
        printf("Invalid Input");
        
    }else{
        printf("Invalid Invalid");
        
    } else{
        printf("%d",gcd(a,b));
    }
    return 0;
}