#!/bin/python3

import sys


n = int(input().strip())
a = list(map(int, input().strip().split(' ')))
temp=0
for i in range(len(a)):
    for j in range(len(a)):
        temp=a[0]-a[1]
        if(abs(a[i]-a[j])<temp):
            temp=abs(a[i]-a[j])
            break
print(temp)