#include <iostream>
using namespace std;

int rec(int x, int a,int n) {
    x++;
    if (a == n) {
        return 0;
    }
    if (x == n) {
        return a * (a - (x*n));
        }
    if (x > 0) {
        return a * rec(x, a, n);
        }
}

int main() {
int a, n, result;
int x = 0;
cout << "A: ";
cin >> a;
cout << "N: ";
cin >> n;
result = rec(x, a, n);
cout << result << endl;
return 0;
}