import java.util.*;

public class Exercise146{
  public static void main (String[] args){

    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();
    int k = sc.nextInt();
    int[] a = new int[n];
    for(int i = 0; i < n; i++){
      a[i] = sc.nextInt();
    }

    Arrays.sort(a);
    System.out.println(a[n - 1] - a[0]);
  }
}