Problem:
Score : 300 points

Problem Statement

Given are an integer X and an integer sequence of length N: p_1, \ldots, p_N.

Among the integers not contained in the sequence p_1, \ldots, p_N (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 \leq X \leq 100

0 \leq N \leq 100

1 \leq p_i \leq 100

p_1, \ldots, p_N are all distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

X N
p_1 ... p_N

Output

Print the answer.

Sample Input 1

6 5
4 7 10 6 5

Sample Output 1

8

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

Sample Input 2

10 5
4 7 10 6 5

Sample Output 2

9

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

100 0

Sample Output 3

100

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

Solution in Python (3.8.2) (judge verdict: Wrong Answer)

import sys

def Forbidden_List(x,n,p):
  #k = [abs(s - x) for s in p]
  #print(k)
  print(x)
  for i in range(n//2 + n%2):
    if x - i not in p: 
        return x - i
    if x + i not in p:
        return x + i
  return x - n//2 - n%2

if __name__ == '__main__':
    input = sys.stdin.readline
    
    inp1 = input().rstrip().split()
    x,n = int(inp1[0]),int(inp1[1])
    if n == 0:
        print(x)
    else: 
        inp2 = input().rstrip().split()
        p = list(map(int,inp2))
        print(Forbidden_List(x,n,p))