atcoder#ABC301G. [ABC301G] Worst Picture

[ABC301G] Worst Picture

Score : 600600 points

Problem Statement

There are NN people in a three-dimensional space. The ii-th person is at the coordinates (Xi,Yi,Zi)(X_i,Y_i,Z_i). All people are at different coordinates, and we have Xi>0X_i>0 for every ii.

You will choose a point p=(x,y,z)p=(x,y,z) such that x<0x<0, and take a photo in the positive xx-direction.

If the point pp and the positions A,BA, B of two people are on the same line in the order p,A,Bp,A,B, then the person at BB will not be in the photo. There are no other potential obstacles.

Find the number of people in the photo when pp is chosen to minimize this number.

Constraints

  • 1N501 \leq N \leq 50
  • 0<Xi10000 < X_i \leq 1000
  • 1000Yi,Zi1000-1000 \leq Y_i,Z_i \leq 1000
  • The triples (Xi,Yi,Zi)(X_i,Y_i,Z_i) are distinct.
  • All values in the input are integers.

Input

The input is given from Standard Input in the following format:

NN

X1X_1 Y1Y_1 Z1Z_1

\vdots

XNX_N YNY_N ZNZ_N

Output

Print the answer.

3
1 1 1
2 2 2
100 99 98
2

For instance, if you take the photo from the point (0.5,0.5,0.5)(-0.5,-0.5,-0.5), it will not show the second person.

8
1 1 1
1 1 -1
1 -1 1
1 -1 -1
3 2 2
3 2 -2
3 -2 2
3 -2 -2
4

If you take the photo from the point (1,0,0)(-1,0,0), it will show four people.