import java.util.*;
public class Average{
	public static void main(String[] arg){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		sc.nextInt();
		int min,max,c;
		min = 1000;
		max = 1;
		for (int i = 0;i < n;i++){
			c = sc.nextInt();
			if(min>c)min = c;
			if(max<c)max=c;
		}
		System.out.println(max-min);
	}
}