#include<stdio.h>
#include<limits.h>
#include<algorithm>
int a,b,c; 
int W[21][21][21];
bool bj[21][21][21];
int w(int x,int y,int z){
    if(x<=0||y<=0||z<=0)return 1;
    if(x>20||y>20||z>20)return w(20,20,20);
    if(bj[x][y][z])return W[x][y][z];
    bj[x][y][z]=true;
    if(a<b&&b<c)return W[x][y][z]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
    return W[x][y][z]=w(a-1,b,c)+w(a-1,b-1,c)+w(a-1,b,c-1)-w(a-1,b-1,c-1);
}
int main(){
    while(a!=-1||b!=-1||c!=-1){
        scanf("%d%d%d",&a,&b,&c);
        if(a!=-1||b!=-1||c!=-1)printf("w(%d, %d, %d) = %d\n",a,b,c,w(a,b,c));
    }
    return 0;
}