import java.util.*;
import java.lang.*;
import java.io.*;

public class Main
{
        public static int minimizeIt(int[] arr, int k) {
         int n=arr.length;
     Arrays.sort(arr);
       int ans = arr[n-1] - arr[0];


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

           int min = Math.min(arr[0]+k, arr[i+1]-k);
           int max = Math.max(arr[n-1]-k ,arr[i]+k);
           ans = Math.min(ans, max-min);
       }
                return ans;
    }

	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner input = new Scanner(System.in);
        int n = input.nextInt();
                  int k = input.nextInt();
        int[] a = new int[n];
        for(int i = 0; i < n; i++){
            a[i] = input.nextInt();
        }
                System.out.println(minimizeIt(a, k));
	}
}