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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Main {


    public static void main(String[] args) {


        Scanner scan = new Scanner(System.in);
int X=scan.nextInt();
        int N =scan.nextInt();


        int M[]=new int[N+1];
        int K=0;
        for(int i=0;i<N;i++) {M[i]=scan.nextInt();
        if (M[i]==X){K=1;}}
M[N]=X;

      int P=X;
        int C=0;
            Arrays.sort(M);
        for(int i=0;i<N&&K==1;i++){ C=0;
            K=0;
        for(int j=N-1;j>=0;j--) {
            if (M[j] == X +i) {
             C= 1;
             P=M[j];
            }

            if (M[j] == X -i&&C==1) {
                K = 1;
                P = M[j];
            }
        }

        }
        if (P>X){System.out.println(2*X-P-1);}
        if (P<X){System.out.println(2*X-P+1);}
        if (P==X){System.out.println(P-1);}




    }
    }