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: Accepted)

function main(input) {
  const inputs =input.split('\n')
  const [X, N] = inputs[0].split(' ').map(Number)
  const P = inputs[1].split(' ').map(Number)
  let min = 101
  let n = -1
  for (let i = 0; i <= 101; i++) {
    // console.log('i:', i)
    if (P.includes(i)) continue
    const d = Math.abs(X - i)
    // console.log('i:', i, 'd:', d)
    if (min <= d) break
    min = d
    n = i
  }
  console.log(n)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))