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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>){
    val a =readLine()!!.split(" ")
    val square :Int = a[0].toInt()
    val trap :Int = a[1].toInt()
    val start :Int = a[2].toInt()
    val b =readLine()!!.split(" ")
    val fee :IntArray = IntArray(trap)
    var countl :Int = 0
    var countr :Int = 0
    for(i in fee.indices){
        fee[i] = b[i].toInt()
    }
    //println(fee.joinToString())
    for(i in 0..trap-1){
        if(fee[i] > 0 && start > fee[i]){
            //  countl.inc()
            countl = countl + 1
        }
        else if(fee[i] > start && square > fee[i]){
            //countr.inc()
            countr = countr + 1
        }
    }
    //println(countr)
    //println(countl)
    val ans :Int = if(countl >= countr) countr else countl
    println(ans)
}