ABC087B - Coins

問題：B - Coins

#include <iostream>
using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)

int main(void) {
    int a, b, c, x, ans = 0;

    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> a;
    cin >> b;
    cin >> c;
    cin >> x;
    REP(i, a + 1) {
        REP(j, b + 1) {
            REP(k, c + 1) {
                if (x == i * 500 + j * 100 + k * 50) {
                    ans++;
                }
            }
        }
    }
    cout << ans << "\n";
    return 0;
}