[문제요약] 중복된 원소가 없고 각 원소가 짝수인 수열이 주어지고 , 구간이 주어질 때 해당 구간에 있는 수 중에서 주어지는 수열의 각 수와의 차이값 중 최소값이 가장 큰 수를 구간에서 찾는 것이다.

입력으로

3 
2 6 16 
1 7 

1 과 7 사이(1 , 7 포함)에 있는 수

• 1 의 경우 min({ |1- 2|,|1-6|,|1-16|} = 1
• ...
• 5 의 경우 min({ |5-2| = 3, |5-6| = 1, |5-16| = 11}) = 1
• 6 의 경우 min({ |6 - 2| = 4, |6 - 6| = 0, |6 - 16| = 10}) = 0
• ...

Brojko and Brojana are expecting an addition to their family and have to come up with a nice name for the little girl. They have decided that the name will be an odd integer in the range [A, B]. Because they find all integers in that range equally beautiful, they have decided to choose the number which maximizes the distance to the name of the closest of the N boys.

More precisely, they seek an odd integer X ∈[A,B] such that the expression min{|X - Pi|,i ∈[1, N]} is as large as possible.

Write a program that determines the name for the little girl. If there are multiple solutions, output any of them.

입력

• The first line contains an integer N (1 ≤ N ≤ 100), the number of boys.
• The second line contains N distinct even integers, the names of the boys. The integers will be less than 10^9 .
• The third line contains the integers A and B (1 ≤ A < B ≤ 10^9), the range of names they are considering for the girl.

출력

입출력 예

input 

3 
2 6 16 
20 50 

output 

49 

input 

3 
2 6 16 
3 15 

output 

11 

input 

3 
2 6 16 
1 7 

output 

5

출처:coci 2007-2008 contest1