import numpy as np
N = int(input())
l = list(set(list(map(int, input().split()))))
l.sort()

if len(l)==1: print(0)

elif len(l)==2: print(l[1]-l[0])

else:
	a = np.array(l)
	d = a[1:N] - a[0:N-1]
	print(min(d))