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)

X_N = [int(i) for i in input().split()]
X = X_N[0]
N = X_N[1]

if N == 100:
    index = 0

elif N != 0:
    p = [int(i) for i in input().split()]
    ary = [i for i in range(1,101)]
    for j in range(N):
        if p[j] in ary:
            ary.remove(p[j])
    min = abs(X-ary[0])
    if ary[0]!=None:
        index = ary[0]
    for j in range(1,len(ary)):
        if min > abs(X-ary[j]):
            min = abs(X-ary[j])
            index = ary[j]

elif N == 0:
    index = X

print(index)