#include <stdio.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <cstdlib>
#include <list>
#include <numeric>
#include <map>
#include <cmath>
#include <string>
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) (x).begin(),(x).end()
using namespace std;
//================================================

int a = 0, b = 0, c, d, n, k = 0;
string s, t;



int main()
{
	int n, h, w;
	cin >> n >> h >> w;
	cout << (n - h + 1) * (n - w + 1) << endl;

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

int main(){
  int a , b , c , d ; 
  cin >> a >> b >> c >> d ; 
  int M = 0 ; 
  
  if(a > b ){
    M += b ;  
  }
  else{
    M =+ a ; 
  }
  
  if(c>d) M += d ; 
  else M += c ; 
  
  cout << M << endl ; 
  
}