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

#define ALL(v) v.begin(), v.end()
#define V vector
#define P pair
using ll = long long;


int main() {
    int n, h, w; cin >> n >> h >> w;

    int a = n - h;
    int b = n - w;
    if(a < 0 || b < 0) {
        cout << 0 << endl;
        return 0;
    }
    a++;
    b++;
    cout << a * b << endl;

     return 0;
}

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define debug(x) cerr << #x << " " << x << '\n'
using namespace std;
using ll = long long;
using pii = pair<int,int>;
using pli = pair<ll,int>;
const int INF = 0x3f3f3f3f, N = 2e5 + 5;
const ll LINF = 1e18 + 5;
int n, h, w; 
int main()
{
 	ios::sync_with_stdio(false);
 	cin.tie(0);
 	cin >> n >> h >> w;
 	int cnt = 0;
 	for(int i=1; i<=n; i++)
 		for(int j=1; j<=n; j++)
 			if(i+h-1<=n && j+w-1<=n) cnt++;
 	cout << cnt;
	return 0;
}
