import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class No21 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		ArrayList<Integer> list = new ArrayList<Integer>();
		for (int i = 0; i < N; i++) {
			list.add(sc.nextInt());
		}

		Collections.sort(list);
		System.out.println(list.get(N - 1) - list.get(0));
	}
}