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: Runtime Error)

# arr=input().strip().split(' ')
x,n=[int(i) for i in input().strip().split(' ')]
arr=[int(i) for i in input().strip().split(' ')]
# neg,pos=[],[]
# for i in arr:
# 	if x-i >0 :
# 		pos.append(x-i)
# 	else:
# 		neg.append(i-x)
# pos=sorted(pos)
# neg=sorted(neg)
diff=[]
for i in arr:
	diff.append(x-i)
i=-1
j=1
while i in diff:
	i=i-1
while j in diff:
	j=j+1
print(min(x+i,x+j))