import java.util.Scanner;
import java.util.TreeSet;
public class No21 {

	public static void main(String[] args) {
		//平均の差
		
		TreeSet<Integer> n = new TreeSet<>();
		
		Scanner s = new Scanner(System.in);
		int N = Integer.parseInt(s.nextLine()) , K = Integer.parseInt(s.nextLine()) , i = 0;
		for(i = 0;i < N;i++) {
			n.add(Integer.parseInt(s.nextLine()));
		}
		s.close();
		
		System.out.println(n.pollLast() - n.pollFirst());

	}

}