N = int(input())
x = list(map(int,input().split()))
i = 0
min = 0
r = 0
x.sort()

while i < N-1:
	if x[i] != x[i-1]:
		r = x[i+ 1] - x[i]
	
	if r < min :
		min = r
	i += 1
		
print(min)