#include <bits/stdc++.h>
using namespace std;
int n, x, y, X1, Y1, X2, Y2, X3, Y3, ans;
int main() {
    cin >> n >> x >> y;
    X1 = x - 1, Y1 = y - 1;
    X2 = n - x, Y2 = y - 1;
    ans = 1 + n * n - (n - min(min(X1, Y1), min(X2, Y2)) * 2) * (n - min(min(X1, Y1), min(X2, Y2)) * 2);
    X3 = min(min(X1, Y1), min(X2, Y2)) + 1, Y3 = min(min(X1, Y1), min(X2, Y2)) + 1;
    if(X3 != x || Y3 != y) Y3++, ans++;
    while(X3 != x || Y3 != y) {
        if(Y3 == min(min(X1, Y1), min(X2, Y2)) + 1) X3--;
        else if(X3 == n - min(min(X1, Y1), min(X2, Y2))) Y3--;
        else if(Y3 == n - min(min(X1, Y1), min(X2, Y2))) X3++;
        else if(X3 == min(min(X1, Y1), min(X2, Y2)) + 1) Y3++;
        ans++;
    }
    cout << ans;
    return 0;
}