# -*- coding: utf-8 -*-
N = input()
inp = map(int, raw_input().split())
inp.sort()
minn = float("inf")
flag = 0
for i in range(0, N-1):
    tmp = inp[i+1] - inp[i]
    if tmp != 0 and tmp < minn:
        minn = tmp
        flag = 1
if flag:
    print minn
else:
    print 0