#include<bits/stdc++.h>
#define ll long long
ll a1[30][30][30];
bool v[30][30][30];
using namespace std;
ll w(ll a, ll b,ll c)
{
	if(a<=0||b<=0||c<=0)
	{
		return 1;
	}else if(v[a][b][c]==true)
	{
		return a1[a][b][c];
	}else if(a>20||b>20||c>20)
	{
		return w(20,20,20);
	}
	if(a<b&&b<c) 
	{
		a1[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
	}else{
		a1[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);
	}
	v[a][b][c]=true;
	return a1[a][b][c];
}
int main()
{
	ll a,b,c;
	while(scanf("%lld%lld%lld",&a,&b,&c))
	{
		if(a==-1&&b==-1&&c==-1)
		{
			break;
		}
		printf("w(%lld, %lld, %lld) = %lld \n",a,b,c,w(a,b,c));
	}
}

为什么hack都RE了