你猜

#include <cstdio>

int gcd(int a, int b) {
    if (b == 0) return a;
    return gcd(b, a % b);
}

int main() {
    int n, m;
    scanf("%d %d", &n, &m);
    printf("%d\n", gcd(n, m));
    return 0;
}