def solution(n, array):
	set_array = set(array)
	if len(set_array) != n:
		return 0
	array.sort()
	min_value = max(array)
	for idx in xrange(len(array)-1):
		if array[idx+1] - array[idx] < min_value:
			min_value = array[idx+1] - array[idx]
	return min_value

n = int(raw_input())
array = map(int, raw_input().split())
print solution(n, array)