2515: C - Forbidden List

Problem Statement

Given are an integer X and an integer sequence of length N:  p1,…,pN.

Among the integers not contained in the sequence  p1,…,pN (not necessarily positive), find the integer nearest to X, that is, find the integer whose absolute difference with X is the minimum. If there are multiple such integers, report the smallest such integer.

Constraints

• 1≤X≤100
• 0≤N≤100
• 1≤pi≤100
• p1,…,pN are all distinct.
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

Output

Print the answer.

Sample Input 1 

Sample Output 1 

Among the integers not contained in the sequence 4,7,10,6,5, the one nearest to 6 is 8.

Sample Input 2

Sample Output 2

Among the integers not contained in the sequence 4,7,10,6,5, the ones nearest to 10 are 9 and 11. We should print the smaller one, 9.

Sample Input 3 

Sample Output 3

When N=0, the second line in the input will be empty. Also, as seen here, X itself can be the answer.

6 5
4 7 10 6 5

8