Problem:
Score : 200 points

Problem Statement

There are N + 1 squares arranged in a row, numbered 0, 1, ..., N from left to right.

Initially, you are in Square X.
You can freely travel between adjacent squares. Your goal is to reach Square 0 or Square N.
However, for each i = 1, 2, ..., M, there is a toll gate in Square A_i, and traveling to Square A_i incurs a cost of 1.
It is guaranteed that there is no toll gate in Square 0, Square X and Square N.

Find the minimum cost incurred before reaching the goal.

Constraints

1 \leq N \leq 100

1 \leq M \leq 100

1 \leq X \leq N - 1

1 \leq A_1 < A_2 < ... < A_M \leq N

A_i \neq X

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M X
A_1 A_2 ... A_M

Output

Print the minimum cost incurred before reaching the goal.

Sample Input 1

5 3 3
1 2 4

Sample Output 1

1

The optimal solution is as follows:

First, travel from Square 3 to Square 4. Here, there is a toll gate in Square 4, so the cost of 1 is incurred.

Then, travel from Square 4 to Square 5. This time, no cost is incurred.

Now, we are in Square 5 and we have reached the goal.

In this case, the total cost incurred is 1.

Sample Input 2

7 3 2
4 5 6

Sample Output 2

0

We may be able to reach the goal at no cost.

Sample Input 3

10 7 5
1 2 3 4 6 8 9

Sample Output 3

3

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);

    int N = 0;
    int M = 0;
    int X = 0;

    while (N < 1 || N > 100) {
      N = sc.nextInt();
    }

    while (M < 1 || M > 100) {
      M = sc.nextInt();
    }

    while (X < 1 || X > N - 1) {
      X = sc.nextInt();
    }

    int[] A = new int[M];
    int s;

    for (int i = 0; i <= M - 1; i++) {
      s = 0;

      while (s < 1 || s > N -1 || s == X) {
        s = sc.nextInt();
      }
      A[i] = s;
    }

    int X2 =X;
    int  c1 = 0;

      while (X2 <= N - 1) {
      for (int ii = 0; ii <= M - 1; ii++) {
        if (A[ii] == X2) {
          c1++;
        }
      }
      X2++;
    }

    X2 =X;
    int  c2 = 0;

      while (X2 >= 0) {
      for (int iii = 0; iii <= M - 1; iii++) {
        if (A[iii] == X2) {
          c2++;
        }
      }
      X2--;
    }

    if (c1 < c2) {
      System.out.println(c1);
    }else {
      System.out.println(c2);
    }


    }
  }