#!/usr/bin/python
# -*- coding: utf-8 -*-

N = int(raw_input())
arr = sorted(set((map(int, raw_input().split()))))

if len(arr) < 2:
	print "0"
	exit()

ans = []
for i in xrange(0,len(arr) - 1):
	ans.append(arr[i+1] - arr[i])

print min(ans)