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 PyPy3 (7.3.0) (judge verdict: Wrong Answer)

#! env python
# -*- coding: utf-8 -*-

import os
import sys


# atcoder.main
# Date: 2020/06/18
# Filename: main 
# Author: acto_mini

def main():
    X, N = map(int, input().split())
    P = list(map(int, input().split()))

    if not X in P:
        print(X)
        exit()

    min_num = 0
    min_dist = 101
    for i in range(0, 101):
        if i in P: continue

        dist = abs(X - i)

        if dist < min_dist:
            min_dist = dist
            min_num = i

    print(min_num)

    return


if __name__ == '__main__':
    main()