#!/bin/python

import sys


n = int(raw_input().strip())
a = map(int, raw_input().strip().split(' '))
# your code goes here
a.sort()

result = []

for i in range(len(a)-1):
    result.append(0)

index = len(a)-1

while index > 0:
    diff = abs(a[index]-a[index-1])
    result[index-1] = diff
    index -= 1

result.sort()

print result[0]