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: Runtime Error)

X, N = map(int, input().split())
p_list = list(map(int, input().split()))
all_list = range(1, 101)

not_p_list = list(set(all_list)-set(p_list))
ans_list = []

for i in not_p_list:
    j = abs(i - X)
    ans_list.append(j)

# print(ans_list)

ans = min(ans_list)
minus_ans = -1 * ans

#print(ans, minus_ans)

if (minus_ans + X) in not_p_list:
    print(minus_ans + X)
else:
    print(ans + X)