# No.135 とりあえず1次元の問題
import sys

n = int(input())
x = [int(i) for i in input().split()]

if x == [] or len(x) <= 1:
    print(0)

minimum = sys.maxsize

for i in range(n):
    for j in range(i + 1, n):
        minimum = min(minimum, abs(x[i] - x[j]))

print(minimum)