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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

const toInt = x=>parseInt(x,10);
const toIntArr = arr=>arr.map(x=>toInt(x));
const abs = x=>x>0?x:-x;
function min(){let rest = arguments,val=rest[0];for(let i=1;i<rest.length;i++)if(rest[i]<val)val = rest[i];return val}
function max(){let rest = arguments,val=rest[0];for(let i=1;i<rest.length;i++)if(rest[i]>val)val = rest[i];return val}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));
 
function Main(inputText){
	let input = inputText.split('\n');
	input = input.map(e => toIntArr(e.split(' ')));
	let x = input[0][0], n = input[0][1], ps = input[1];
	if(n===0){
		console.log(x);return 0;
	}
	let ans = 1000;
	for(let i = -100; i < 100; i++){
		if(ps.indexOf(i+1)===-1 && (i+1-x)<abs(ans)) ans = i+1-x;
	}
	console.log(ans+x);
	return 0;
}