#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  ll n, h, w;
  cin >> n >> h >> w;
  cout << (n / 2) * (n - n / 2) * (h + w - 2) << '\n';
  return 0;
}