#coding: utf-8
##yuki_135
import sys

x=int(raw_input())
s=[]
s=map(int,raw_input().split())

s.sort()

dif=10**6+1
for i in xrange(1,len(s)):
 if s[-1]==0:
  print 0
  sys.exit()
 if s[i]==s[i-1]:
  continue
 d=s[i]-s[i-1]
 dif=min(d,dif)
print dif