using namespace std;
const int N=25;
int f[N][N][N];
long long w(long  a, long b, 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 w(20,20,20);
	if(a<b&&b<c) f[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
	else f[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);
	return f[a][b][c];
}  
int main(){
	long long a,b,c;
	while(cin>>a>>b>>c){
		if(a==-1&&b==-1&&c==-1)
			break;
		cout<<"w("<<a<<", "<<b<<", "<<c<<") = ";
		cout<<w(a,b,c)<<endl;
	}
	return 0;
}```