#include<stdio.h>
int gcd(int a, int b) {
    if (b==0) {
        return a;
    }
    return gcd(b, a % b);
}
int main() {
    int num1,num2;
    printf("Enter two positive integers",num1, num2);
    scanf("%d %d", &num1, &num2);
    
    if(num1 < 0 || num2 < 0) {
        printf("Invalid input\n");
        return 1;
    }
    int result = gcd(num1, num2);
    printf("%d\n", result);
    return 0;
}