# 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
x.sort()

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

print(minimum if minimum != sys.maxsize else 0)