import java.util.Scanner;

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

		int n = sc.nextInt(), t = sc.nextInt(), max = 0, min = 1000;
		for(int i = 0; i < n; i++){
			t = sc.nextInt();
			max = Math.max(max, t);
			min = Math.min(min, t);
		}
		System.out.println(max-min);
	}
}