# coding=UTF-8
# import statistics

n = int(input())
l = list(map(int, input().split()))
s_l = set(l)
num_list = list(s_l)
pointA = list(num_list[:len(s_l)])
pointB = list(num_list[1:])
mile_list = list()
for i, j in zip(pointA, pointB):
    mile_list.append(abs(i-j))
print(mile_list[-1])