Moon Game

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <list>
#include <algorithm>
#include<queue>
#include<vector>
#include<set>
#include<cmath>
 
using namespace std;
int n;
int x[35];
int y[35];
int qu(int a,int b,int c)
{
    return (x[b]-x[a])*(y[c]-y[a])-(y[b]-y[a])*(x[c]-x[a]);
}
int build(int a,int b,int c,int d)
{
 
//   cout<<qu(a,b,d)<<" ";
//   cout<<qu(b,c,a)<<" ";
//   cout<<qu(c,d,b)<<" ";
//   cout<<qu(d,a,c)<<" "<<endl;;
    if(qu(a,b,d)<=0)
      return 0;
    if(qu(b,c,a)<=0)
     return 0;
    if(qu(c,d,b)<=0)
     return 0;
    if(qu(d,a,c)<=0)
     return 0;
    return 1;
}
int main()
{
    int T;
    cin>>T;
    for(int k=1;k<=T;k++)
    {
        cin>>n;
        for(int i=0;i<n;i++)
        {
            cin>>x[i]>>y[i];
        }
        //s.clear();
        int num=0;
        for(int i=0;i<n;i++)
            for(int j=i+1;j<n;j++)
              for(int a=j+1;a<n;a++)
                for(int b=a+1;b<n;b++)
               {
                   //cout<<"No   d"<<endl;
                  if(build(i,a,b,j)) { num++; continue;}
                  if(build(i,j,b,a)) { num++; continue;}
                  if(build(i,b,a,j)) { num++; continue;}
                  if(build(i,j,a,b)) { num++; continue;}
                  if(build(i,a,j,b)) { num++; continue;}
                  if(build(i,b,j,a)) { num++; continue;}
 
               }
         printf("Case %d: ",k);
         cout<<num<<endl;
    }
    return 0;
}