#include <iostream>
#include <map>
#include <algorithm>
#include <string>
#include <vector> 
#include <numeric>
#include <cmath>
#include <queue>
#include <iomanip>
#include <functional>

#define CHMAX(a,b) a = std::max(a,b)
#define CHMIN(a,b) a = std::min(a,b)
#define CHABS(a) a = std::abs(a) 
#define COUT(a) std::cout << a << std::endl
#define CERR(a) std::cerr << a << std::endl
#define FOR(n) for(lli i = 0; i < n; i++)

using namespace std;
using lli = long long int;
using pll = pair<lli, lli>;
using tlll = tuple<lli, lli, lli>;
using vll = vector<lli>;

lli mod197 = 1000000007LL;
lli INF = 10000000000000;

// ax + by = gcd(a,b) 最大公約数
template< typename T >
T extgcd(T a, T b, T& x, T& y) {
	T d = a;
	if (b != 0) {
		d = extgcd(b, a % b, y, x);
		y -= (a / b) * x;
	}
	else {
		x = 1;
		y = 0;
	}
	return d;
}


int main(void) {

	int n, h, w;
	cin >> n >> h >> w;

	COUT((n - h + 1) * (n - w + 1));





	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;
}