Project Euler #31 : Coin sums

int main() {
    int cnt = 0;
    for (int a = 0; a * 200 <= 200; a++) {
        for (int b = 0; a * 200 + b * 100 <= 200; b++) {
            for (int c = 0; a * 200 + b * 100 + c * 50 <= 200; c++) {
                for (int d = 0; a * 200 + b * 100 + c * 50 + d * 20 <= 200; d++) {
                    for (int e = 0; a * 200 + b * 100 + c * 50 + d * 20 + e * 10 <= 200; e++) {
                        for (int f = 0; a * 200 + b * 100 + c * 50 + d * 20 + e * 10 + f * 5 <= 200; f++) {
                            for (int g = 0; a * 200 + b * 100 + c * 50 + d * 20 + e * 10 + f * 5 + g * 2 <= 200; g++) {
                                cnt++;
                            }
                        }
                    }
                }
            }
        }
    }
    cout << cnt;
}