import sys
import numpy as np

N = int(input())

if N == 1:
    print(0)
    sys.exit()

l = sorted([int(i) for i in input().split()], reverse=True)

diff_close_l = []


diff_close_l = np.diff(l,n=1)

#for i in range(N - 1):
#    diff_close_l.append(l[i] - l[i + 1])

while 0 in diff_close_l:
    diff_close_l.remove(0)

if len(diff_close_l) == 0:
    print(0)
    sys.exit()

print(min(diff_close_l))