using System;

public class Program {
	public static void Main(string[] args) {
		int n = int.Parse(Console.ReadLine());
		Console.ReadLine();  // k
		int min = 1000;
		int max = 1;
		for (int i = 0; i < n; i++) {
			int num = int.Parse(Console.ReadLine());
			if (num < min) {
				min = num;
			}
			if (num > max) {
				max = num;
			}
		}
		Console.WriteLine(max-min);
	}
}