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

int main() { long long a, b, c; cin >> a >> b >> c; printf("%lld", (a * b * 2) + (a * c * 2) + (b * c * 2)); return 0; }

#include <bits/stdc++.h>

using namespace std; int main() { long long a, b, h; cin >> a >> b >> h; cout << (a * b + a * h + b * h) * 2; return 0; }