P9184.cpp

#include <iostream>

using namespace std;

int dp[21][21][21] = {};

int w(int a, int b, int c) {
    if (a <= 0 || b <= 0 || c <= 0) {
        return 1;
    } else if (a > 20 || b > 20 || c > 20) {
        return w(20, 20, 20);
    } else if (dp[a][b][c] != 0) {
        return dp[a][b][c];
    } else if (a < b && b < c) {
        dp[a][b][c] = w(a, b, c - 1) + w(a, b - 1, c - 1) - w(a, b - 1, c);
    } else {
        dp[a][b][c] = w(a - 1, b, c) + w(a - 1, b - 1, c) + w(a - 1, b, c - 1) - w(a - 1, b - 1, c - 1);
    }

    return dp[a][b][c];

}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    while (1) {
        int a, b, c;
        cin >> a >> b >> c;

        if (a == -1 && b == -1 && c == -1) break;

        cout << "w(" << a << ", " << b << ", " << c << ") = " << w(a, b, c) << "\n";

    }

    return 0;
}