#!/bin/python3

import sys


n = int(input().strip())
a = list(map(int, input().strip().split(' ')))
b=[]
# your code goes here
if n<2 or n>pow(10,5):
    print('invalid')
for i in range(0,n-1):
    if a[i]<pow(-10,9) or a[i]>pow(10,9):
        print('invalid')
    else:
        b.append(abs(a[i]-a[i+1]))
b.append(abs(a[0]-a[n-1]))
print(min(b))