input()
nums = input().split()
for i in range(len(nums)):
	nums[i] = int(nums[i])
nums = list(set(nums))
nums.sort()
min = 1000000
if(len(nums) == 1):
	print('0')
else:
	for i in range(len(nums)-1):
		if(nums[i+1] - nums[i] < min):
			min = nums[i+1] - nums[i]
	print(min)