import itertools

n = input()
l = input().split()
lint = [int(i) for i in l]
lint.sort()
slit = list(lint for lint, _ in itertools.groupby(lint))

if len(slit) < 2:
    print("0")
else:
    mlen = slit[1] - slit[0]
    for i in range(1, len(slit)-1):
        if slit[i+1] - slit[i] < mlen:
            mlen = slit[i+1] - slit[i]
    print(mlen)