#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; ++i)
#define all(a) (a).begin(), (a).end()

int main() {
    cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    
    ll N, H, W;
    cin >> N >> H >> W;
    
    cout << (N / 2) * ((N + 1) / 2) * (H + W - 2) << '\n';
}