#include<bits/stdc++.h>
using namespace std;
long long wc[110][110][110]; //3个参数3个数组 
long long w(long long a,long long b,long long c){
	if(a<=0||b<=0||c<=0) return 1;
	else if(wc[a][b][c]!=0) return wc[a][b][c];
	else if(a>20||b>20||c>20) wc[a][b][c]=w(20,20,20);
	else if(a<b&&b<c) wc[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
	else wc[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 wc[a][b][c];
}
signed main(){
	long long a,b,c;
	while(scanf("%lld%lld%lld",&a,&b,&c)==3){ //记忆化搜索 
        if(a!=-1&&b!=-1&&c!=-1) printf("w(%lld, %lld, %lld) = ",a,b,c);
        else  break;
        printf("%lld\n",w(a,b,c));
	}
	return 0;
}