import java.util.Scanner;

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

		int N = in.nextInt();
		int k = in.nextInt();

		int min = in.nextInt();
		int max = in.nextInt();
		if (max < min) {
			int t = max;
			max = min;
			min = t;
		}
		for (int i = 0; i < N - 2; i++) {
			int val = in.nextInt();
			if (max < val)
				max = val;
			if (min > val)
				min = val;
		}
		System.out.println(max - min);
	}
}