#include <iostream>


using namespace std;

int g_c_d(int a, int b) {
    if (a == b) {
        return a;
    }
    return a > b ? g_c_d(a - b, b) : g_c_d(a, b - a);
}


int main() {
    setlocale(LC_ALL, "ru");

    cout << g_c_d(3, 8) << endl;
    cout << g_c_d(25, 125) << endl;
    cout << g_c_d(6, 9) << endl;
}