import java.util.Arrays;
import java.util.Scanner;

public class Yukicoder21 {

	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.length - 1] - n[0]);
	}
}