N = map(int, raw_input())
xs = list( map(int, raw_input().split()) )
xs = set(xs)
xs = list(xs)
xs.sort()
if len(xs) <= 1:
	print 0
else:
	mins = []
	for i in range(len(xs) -1):
		mins.append(abs(xs[i] - xs[i+1]))
	print min(mins)