#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    ll N, H, W;
    cin >> N >> H >> W;
    cout << (N / 2) * ((N + 1) / 2) * (H + W - 2) << endl;
}