#!/bin/python

import sys


n = int(raw_input().strip())
elements = map(int, raw_input().strip().split(' '))

if len(list(set(elements))) != len(elements):
    print 0
else:
    elements_no_rep = list(set(elements))
    elements_no_rep.sort()
    ab_dif = abs(elements_no_rep[0] - elements_no_rep[1])
    old = elements_no_rep[1]
    for element in elements_no_rep[2:]:
        if abs(old - element) < ab_dif:
            ab_dif = abs(old - element)
        old = element
    print ab_dif