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

	public static void main(String[] args) {
		//平均の差
		
		Scanner s = new Scanner(System.in);
		int N = Integer.parseInt(s.nextLine()) , K = Integer.parseInt(s.nextLine()) , i = 0;
		int[] n = new int[N];
		for(i = 0;i < N;i++) {
			n[i] = Integer.parseInt(s.nextLine());
		}
		s.close();
		Arrays.sort(n);
		
		System.out.println(n[n.length-1] - n[0]);

	}

}