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

if __name__ == "__main__":
	n = input()
	nums = map(int,raw_input().split())
	nums = list(set(nums))
	nums.sort()
	mini = float("INF")
	if len(nums) == 1:
		print 0
		sys.exit()
	for i in xrange(0,len(nums)-1):
		mini = min(nums[i+1]-nums[i], mini)
	print mini