#include<iostream>
#include<cstring>
using namespace std;

long long f[21][21][21] = { 0 };
long long dfs(long long a, long long b, long long c)
{	
	if (a <= 0 || b <= 0 || c <= 0)
		return 1;
	if (f[a][b][c])
		return f[a][b][c];
	if (a > 20 || b > 20 || c > 20)
		return f[20][20][20];
	if (a < b&&b < c)
		return f[a][b][c] = dfs(a, b, c - 1) + dfs(a, b - 1, c - 1) - dfs(a, b - 1, c);
	return f[a][b][c] = dfs(a - 1, b, c) + dfs(a - 1, b - 1, c) + dfs(a - 1, b, c - 1) - dfs(a - 1, b - 1, c - 1);
}

int main()
{
	long long x, y, z;
	while (cin>>x>>y>>z) {
		if (x ==-1&& y ==-1&& z == -1)
			break;
		memset(f, 0, sizeof(f));
		dfs(x, y, z);
		cout << "w(" << x << ", " << y << ", " << z << ") = " << f[x][y][z] << endl;
	}

	return 0;
}