n = int(input())
li = list(map(int, input().split()))
li.sort()
dif = []
if len(li) >= 2:
    for i in range(len(li) - 1):
        if not li[i + 1] == li[i]:
            dif.append(li[i + 1] - li[i])
    if len(dif) >= 1:
        print(min(dif))
    else:
        print('0')
else:
    print('0')