#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

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

    return 0;
}