import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int K = sc.nextInt();
    int[] n = new int[N];
    for(int i = 0; i < N; i++) {
      n[i] = sc.nextInt();
    }
    Arrays.sort(n);
    System.out.println(n[N - 1] - n[0]);
  }
}