시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
1 초 128 MB 75 14 10 20.408%

문제

상근이는 공항에서 수화물 찾는 곳의 원형 컨베이어 벨트에 짐이 충돌하지 짐을 놓는 일을 하고 있다. 모든 짐은 직선 컨베이어 벨트를 이용해서 운반되어 원형 컨베이어 벨트로 떨어지게 된다. 상근이는 직선 컨베이어 벨트의 속도를 조절해서 짐이 서로 충돌하지 않게 조절한다. 

상근이는 직선 컨베이어 벨트의 속도를 고정해놓은 다음 화장실을 다녀오려고 한다. 직선 컨베이어 벨트에는 센서가 있어, 상근이는 모든 짐의 위치를 알고 있다. 짐이 충돌하지 않는 직선 컨베이어 벨트의 최대 속도를 구하는 프로그램을 작성하시오.

원형 컨베이어 벨트는 1m/s 속도로 이동한다. 짐이 원형 컨베이어 벨트에 떨어졌을 때, 1m 내에 짐이 있다면, 그 짐과 충돌한다. 중간에 사람들이 짐을 집어갈 수 있지만, 어떤 짐을 집어가는지는 알 수 없기 때문에, 짐을 가져가는 경우는 없다고 가정한다. 직선 컨베이어 벨트는 0.1m/s와 10m/s 사이의 속도로 움직일 수 있다.

입력

첫째 줄에 짐의 수 N과 원형 컨베이어 벨트의 길이 L (1 ≤ N ≤ L ≤ 1000)이 주어진다. 둘째 줄에는 짐의 위치 (단위: 미터) xi가 주어진다. (0 ≤ xi ≤ 1000) xi는 소수점 둘째자리 까지 주어진다.

출력

모든 짐이 충돌하지 않는 최대 속도 v (단위: m/s)를 출력한다. 그러한 속도가 없는 경우에는 "no fika"를 출력한다. 정답과 절대 오차가 최대 10-9인 경우에 정답이다.

v가 정답인 경우에, 구간 [v-10-9, v]에 해당하는 속도도 올바른 정답이다.

예제 입력 1

2 3
0.00 2.00

예제 출력 1

2

예제 입력 2

3 4
0.05 1.00 3.50

예제 출력 2

0.5
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