#!/bin/python3

import sys

seen_numbers = set()
found = False
smallest = None

n = int(input().strip())
for i in map(int, input().strip().split(' ')):
    if i in seen_numbers:
        print('0')
        found = True
        break
    seen_numbers.add(i)

if not found:
    sorted_list = sorted(seen_numbers)
    for i in range(len(sorted_list)-1):
        small = abs(sorted_list[i]-sorted_list[i+1])
        if smallest == None:
            smallest = small
        elif small < smallest:
            smallest = small
        
    print(smallest)