#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int N = 25;
ll mem[N][N][N];
ll w(ll a, ll b, ll c) {
if (a <= 0 || b <= 0 || c <= 0) return 1;
else if (a > 20 || b > 20 || c > 20)
return w(20, 20, 20);
if (mem[a][b][c] != -1) return mem[a][b][c];
else if (a < b && b < c)
return mem[a][b][c] = w(a, b, c - 1) + w(a, b - 1, c - 1) - w(a, b - 1, c);
else return mem[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() {
ll a, b, c;
memset(mem, -1, sizeof(mem));
while (cin >> a >> b >> c) {
if (a == -1 && b == a && c == b) break;
cout << "w(" << a << ", " << b << ", " << c << ") = " << w(a, b, c) << endl;
}
return 0;
}