样例可以过，但测试点0分求帮助[哭]

using namespace std;

const int N=1E3+10;
long long f[21][21][21];

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

int main(){
	long long n,m,u;
	while(1){
		cin>>n>>m>>u;
		if(n==-1&&m==-1&&u==-1) break;
		cout<<"w("<<n<<", "<<m<<", "<<u<<") = "<<w(n,m,u)<<endl;
	}
	return 0;
}