import java.util.Scanner;

public class Main21 {
	public static void main(String[] args) {
		Main21 p = new Main21();
	}

	public Main21() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		int[] a = new int[n];
		for(int i=0;i<a.length;i++)
			a[i] = sc.nextInt();
		solve(k, a);
	}

	public void solve(int k, int[] a) {
		int min = Integer.MAX_VALUE;
		int max = 0;
		
		for(int i=0;i<a.length;i++){
			min = Math.min(min, a[i]);
			max = Math.max(max, a[i]);
		}
		
		System.out.println(max-min);
	}

}