시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
4 초 256 MB 178 30 17 21.250%

문제

Annabel and Richard like to invent new games and play against each other. One day Annabel has a new game for Richard. In this game there is a game master and a player. The game master draws n points on a piece of paper. The task for the player is to find a straight line, such that at least p percent of the points lie exactly on that line. Richard and Annabel have very good tools for measurement and drawing. Therefore they can check whether a point lies exactly on a line or not. If the player can find such a line then the player wins. Otherwise the game master wins the game.

There is just one problem. The game master can draw the points in a way such that it is not possible at all to draw a suitable line. They need an independent mechanism to check whether there even exists a line containing at least p percent of the points, i.e., dn · p/100e points. Now it is up to you to help them and write a program to solve this task.

입력

The input consists of:

  • one line with one integer n (1 ≤ n ≤ 105), the number of points the game master has drawn;
  • one line with one integer p (20 ≤ p ≤ 100), the percentage of points which need to lie on the line;
  • n lines each with two integers x and y (0 ≤ x, y ≤ 109), the coordinates of a point.

No two points will coincide.

출력

Output one line containing either “possible” if it is possible to find a suitable line or “impossible” otherwise.

예제 입력

5
55
0 0
10 10
10 0
0 10
3 3

예제 출력

possible

예제 입력 2

5
45
0 0
10 10
10 0
0 10
3 4

예제 출력 2

impossible

힌트

(a) Sample input 1: A line with (at least) 3 of the points exists.

(b) Sample input 2: No line with at least 3 points exists.