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: Runtime Error)


import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String[] str1 = sc.nextLine().split(" ");
    String[] str2 = sc.nextLine().split(" ");
    int x = Integer.parseInt(str1[0]);
    int n = Integer.parseInt(str1[1]);
    int index = x - 1;

    int[] num = new int[100];

    for(int i = 0 ; i < 100;i++) {
      num[i] = i+1;
    }

    for(int i = 0;i < n;i++) {
      num[Integer.parseInt(str2[i]) - 1] = -1;
    }
    int minIndex = -1;
    int maxIndex = -1;

    for(int i = 0 ; i < 100;i++) {
      if(i < index) {
        if(num[i] != -1) {
          minIndex = i;
        }
      }else {
        if(num[i] != -1) {
          maxIndex = i;
          break;
        }
      }
    }

    int ans = 0;
    if(minIndex != -1 && maxIndex != -1) {
      if(x - num[minIndex] <= num[maxIndex] - x) {
        ans = num[minIndex];
      }else {
        ans = num[maxIndex];
      }
    }else if(minIndex != -1 && maxIndex == -1) {
      ans = num[minIndex];
    }else {
      ans = num[maxIndex];
    }


    if(x == 100 && num[98] == -1) {
      ans = 101;
    }else if(x == 1 && num[1] == -1) {
      ans = 0;
    }

    System.out.println(ans);

  }

}