n = int(input())
li = list(set(map(int, input().split())))
li.sort
dif = []

if not len(li) == 0:
    for i in range(len(li) - 1):
        if li[i + 1] - li[i] >= 0:
            dif.append(li[i + 1] - li[i])

print(min(dif))