import java.util.Arrays;
import java.util.Scanner;
public class No21 {
    public static void main(String[] args) {
        Scanner sc =new Scanner(System.in);
        int N = sc.nextInt();
        sc.nextInt();
        int[] n = new int[N];
        for (int i = 0; i < N; i++)n[i] = sc.nextInt();
        Arrays.sort(n);
        System.out.println(n[n.length - 1] - n[0]);
    }
}