#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
#define all(x) (x).begin(), (x).end()
#define endl '\n'
#define fsp(x) cout << fixed << setprecision(x)
const ll inf = LLONG_MAX;
const long double pi = M_PI;
void Yes() {cout << "Yes" << endl;}
void No() {cout << "No" << endl;}
void YES() {cout << "YES" << endl;}
void NO() {cout << "NO" << endl;}

int main() {
  ll n, h, w;
  cin >> n >> h >> w;
  ll ans = (n - h + 1) * (n - w + 1);
  cout  << ans << endl;
}
#include <bits/stdc++.h>
using namespace std;

int main() {
  int N, H, W;
  cin >> N >> H >> W;

  int cnt = 0;
  for (int i = H; i <= N; i++) {
    for (int j = W; j <= N; j++) {
      if (N >= i && N >= j) cnt++;
    }
  }

  cout << cnt << endl;
}