# -*- coding: utf-8 -*-
import math

n = int(input())
k = int(input())
n_box = []
for _ in range(n):
    n_box.append(int(input()))
nbox_sort = sorted(n_box)

nbox_min = (nbox_sort[0])
nbox_max = nbox_sort[-1]
print(math.ceil(nbox_max - nbox_min))