#include <bits/stdc++.h>

 using namespace std;

 const int maxn=;

 struct Point

 {

     int x,y;

     double rad;

     bool operator < (const Point &rhs) const{

         return rad<rhs.rad;

     }

 }op[maxn],p[maxn];

 int n,color[maxn];

 bool left(Point A,Point B)

 {

     return A.x*B.y - A.y*B.x >= ;

 }

 int solve()

 {

     if(n<=) return ;

     int ans=;

     for(int i=;i<n;i++)

     {

         int k=;

         //极角排序

         for(int j=;j<n;j++)

             if(j!=i)

             {

                 p[k].x=op[j].x-op[i].x;

                 p[k].y=op[j].y-op[i].y;

                 if(color[j])

                 {

                     p[k].x = -p[k].x; p[k].y = -p[k].y;

                 }

                 p[k].rad=atan2(p[k].y , p[k].x);

                 k++;

             }

         sort(p,p+k);

         //滑动

         int L= , R= , cnt=;

         while(L < k)

         {

             if(R==L) {  R = (R+)%k; cnt++;  }

             while(R != L && left(p[L] , p[R]))

             {

                 R = (R+)%k; cnt++;

             }

             cnt--; L++;

             ans=max(ans,cnt);

         }

     }

     return ans;

 }

 int main()

 {

     while(scanf("%d",&n)== && n)

     {

         for(int i=;i<n;i++)

             scanf("%d%d%d", &op[i].x, &op[i].y, &color[i]);

         printf("%d\n",solve());

     }

     return ;

 }