#coding:utf-8

from math import fabs

N=input()
X=map(int,raw_input().split())

sorted(X)

n=set()
for i in range(N-1):
	n.add(fabs(X[i]-X[i+1]))

n.add(fabs(X[-1]-X[-2]))

if 0 in n:
	n.remove(0) 
	print int(min(n))
else:
	print int(min(n))