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

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];
		Arrays.setAll(n, i -> sc.nextInt());
		int min = Arrays.stream(n).min().getAsInt();
		int max = Arrays.stream(n).max().getAsInt();

		System.out.println(max - min);

		sc.close();
	}
}