#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

ll gcd(ll a, ll b) {
  if(!a) return b;
  return gcd(b % a, a);
}

ll lcm(ll a, ll b) {
    return a * b / gcd(a, b);
}

int main() {
  cout << gcd(12, 18) << endl;
  cout << gcd(0, 18) << endl;
  cout << lcm(12, 18) << endl;
  return 0;
}