Problem: 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.

Submission attempts (in order):
import sys
# from collections import deque
# from collections import Counter
# from math import sqrt
# from math import log
# from math import ceil


# 	if(a==0):
# 		return b 




# 	p=2
# 	while(p*p<=n): 



# 		p+=1


# 	s=set()


# 		s.add(i)


# alpha=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
# mod=10**9+7

fast_reader=sys.stdin.readline
fast_writer=sys.stdout.write

def input():
	return fast_reader().strip()

def print(*argv):
	fast_writer(' '.join((str(i)) for i in argv))
	fast_writer('\n')

def list_input():
	return list(map(int, input().split()))

def sep_input():
	return map(int, input().split())

#_______________________________________________________________________________________________________________________________________

x,n=sep_input()
l=list_input()
s=set(l)
i=0
while(True):
	if(x-i not in s):
		print(x+i)
		break
	elif(x+i not in s):
		print(x-i)
		break
	else:
		i+=1

import sys
# from collections import deque
# from collections import Counter
# from math import sqrt
# from math import log
# from math import ceil


# 	if(a==0):
# 		return b 




# 	p=2
# 	while(p*p<=n): 



# 		p+=1


# 	s=set()


# 		s.add(i)


# alpha=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
# mod=10**9+7

fast_reader=sys.stdin.readline
fast_writer=sys.stdout.write

def input():
	return fast_reader().strip()

def print(*argv):
	fast_writer(' '.join((str(i)) for i in argv))
	fast_writer('\n')

def list_input():
	return list(map(int, input().split()))

def sep_input():
	return map(int, input().split())

#_______________________________________________________________________________________________________________________________________

x,n=sep_input()
l=list_input()
s=set(l)
i=0
while(True):
	if(x+i in s):
		print(x+i)
		break
	elif(x-i in s):
		print(x-i)
		break
	else:
		i+=1

import sys
# from collections import deque
# from collections import Counter
# from math import sqrt
# from math import log
# from math import ceil


# 	if(a==0):
# 		return b 




# 	p=2
# 	while(p*p<=n): 



# 		p+=1


# 	s=set()


# 		s.add(i)


# alpha=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
# mod=10**9+7

fast_reader=sys.stdin.readline
fast_writer=sys.stdout.write

def input():
	return fast_reader().strip()

def print(*argv):
	fast_writer(' '.join((str(i)) for i in argv))
	fast_writer('\n')

def list_input():
	return list(map(int, input().split()))

def sep_input():
	return map(int, input().split())

#_______________________________________________________________________________________________________________________________________

x,n=sep_input()
l=list_input()
s=set(l)
i=0
while(True):
	if(x-i not in s):
		print(x-i)
		break
	elif(x+i not in s):
		print(x+i)
		break
	else:
		i+=1

Verdicts: Wrong Answer

Wrong Answer

Accepted