#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
#define all(x) x.begin(),x.end()
#define rep(i,j,n) for (long long i = j; i < (long long)(n); i++)
#define _GLIBCXX_DEBUG
const ll MOD = 1000000007;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//(a+b-1)/b
//priority_queue<ll, vector<ll>, greater<ll>> q;

signed main(){
	ll n,a,b; cin>>n>>a>>b;
	cout<<(n-a+1)*(n-b+1)<<endl;



	return 0;
}
#include <bits/stdc++.h>
using namespace std;

int main() {
  int n,h,w;
  cin >> n >> h >> w;
  int a = 0;
  int b = 0;
  for(int i = 1; i <= n; i++){
    if(i+w-1 <= n) a++;
    if(i+h-1 <= n) b++;
  }
  cout << a*b << endl;
  return 0;
}