03. Combinations

#include <iostream>

using namespace std;

int main() {

    int num;
    cin >> num;

    int counter = 0;

    for (int a = 0; a <= num; a++) {
        for (int b = 0; b <= num; b++) {
            for (int c = 0; c <= num; c++) {
                if (a + b + c == num) {
                    counter++;
                }
            }
        }
    }

    cout << counter<< endl;

    return 0;
}