n = int(input())
x = list(map(int, input().split()))
x = sorted(list(set(x)))
if len(x) == 1:
    print(0)
else:
    num = float("inf")
    pre = x[0]
    for i in range(1, len(x)):
        num = min(num, x[i] - pre)
        pre = x[i]

    print(num)