# -*- coding: utf-8 -*-

n = int(input())
x = list(map(int,input().split()))

minlen = 100000000

for i in range(n):
    for j in range(i+1,n):
        if x[i] != x[j]:
            minlen = min(minlen, abs(x[i] - x[j]))

if minlen == 100000000:
    minlen = 0

print(minlen)