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)

//var input = "100 0"

function main(input){
  var input = input.trim();
  var input = input.split("\n");
  var kazu = parseInt(input[0].split(" ")[0]);
  var answer = kazu;
  if(input[1]){var fList = input[1].split(" ");}
  else{fList=[];}
  for(var i=0; i<fList.length; i++){fList[i]=parseInt(fList[i]);}
  var nList = [];
  for(var i=-10; i<101; i++){
    if(fList.includes(i)==false && i!=0){
      nList[nList.length]=[i,Math.abs(kazu-i)];
    }
  }
  // console.log(nList);
  nList.sort(function (a, b) {
    return (a[1] - b[1]);
  });
  console.log(nList[0][0]);
  // console.log(nList);
}//main(input);
main(require("fs").readFileSync("/dev/stdin", "utf8"));