2D Geometry
시간 제한1초메모리 제한1024 MB
서로 다른 n개의 점에서 넓이가 양수인 삼각형을 이루는 세 점을 반복해 지울 때 남길 수 있는 최소 점의 수를 구한다.
문제
There are distinct points on a 2-dimension plane. The coordinates of the -th point is .
If there are three points , and which form a triangle with positive area, Bobo can remove them simultaneously from the plane. Also, if there are multiple triangles with positive area, Bobo can choose to remove any of them. Find the minimum number of points left on the plane if he can perform the operation for any number of times.
입력
The input consists of several test cases terminated by end-of-file. For each test case,
The first line contains an integer .
For the following lines, the -th line contains two integers and .
출력
For each test case, output an integer which denotes the minimum number of points left.
제한
- for each
- for each
- In each input, the sum of does not exceed .
힌트
For the third test case, if Bobo chooses to remove the triangle first, there will be no other triangles to remove. Alternatively, Bobo can remove the triangle first and then .