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)

# coding: utf-8
# Your code here!
x,n=map(int,input().split())
if n!=0:
    a=list(map(int,input().split()))
else:
    a=[0]*3
number=[0]*101

for num in range(len(a)):
    number[a[num]]=a[num]
    
counter=0
plus=0
ans=0

while counter==0:
    if number[x-plus]==0:
        counter+=1
        ans=x-plus
    elif number[x+plus]==0:
        counter+=1
        ans=x+plus
    else:
        plus+=1
        if plus>x or plus>(100-x):
            counter+=1
            ans=0

print(ans)