import java.util.*;
 

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int max=0;
		int min=Integer.MAX_VALUE;
		for(int i=0;i<n;i++){
			int temp=sc.nextInt();
			max=Math.max(max, temp);
			min=Math.min(min, temp);
		}
		System.out.println(max-min);
	}
}