# No.135 とりあえず1次元の問題
def getMin(minimum, nums):
    if len(nums) == 1:
        return 0
    if len(nums) == 2:
        return abs(nums[0] - nums[1])

    first = nums[0]
    others = nums[1:]

    minimun = abs(first - nums[1])

    for i in nums[2:]:
        if minimum > abs(first - i):
            minimum = abs(first - i)

    return getMin(minimum, others)
    
n = int(input())
x = [int(i) for i in input().split()]

print(getMin(0, x))