#include <iostream>
using namespace std;

int memo[21][21][21];

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

int main() {
    int a, b, c;
    for (int i = 0; i <= 20; ++i)
        for (int j = 0; j <= 20; ++j)
            for (int k = 0; k <= 20; ++k)
                memo[i][j][k] = -1;

    while (cin >> a >> b >> c) {
        if (a == -1 && b == -1 && c == -1) break;
        cout << "w(" << a << ", " << b << ", " << c << ") = " << w(a, b, c) << endl;
    }
    return 0;
}