import java.util.Scanner;

class Main {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);

		int N = in.nextInt();
		int K = in.nextInt();
		int max = in.nextInt();
		int min = in.nextInt();
		for (int i = 2; i < N; i++) {
			int val = in.nextInt();
			if (val > max) {
				max = val;
			}
			if (val < min) {
				min = val;
			}
		}
		System.out.println(max - min);
	}
}