#include <bits/stdc++.h>
using namespace std;
 
using ll = int64_t;
constexpr ll mod = ll(1e9 + 7);
 
int main () {
  ios::sync_with_stdio(0); cin.tie(0);
 
  int TT = 1;
  // cin >> TT;
  while (TT--) {
    ll n,h,w;
    cin >> n >> h >> w;
    --h;
    --w;
    cout << max(ll(0), ((n-h)*(n-w))) << endl;
  }
}

#include <bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int,int> P;
int INF = 1e18;
int mod = 1e9+7;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
signed main() {
    int N,H,W;
    cin >> N >> H >> W;
    cout << (N-H+1)*(N-W+1) << endl;
}
