list = input().lstrip('[').rstrip(']').split(',')
size = len(list)
if size < 2:
    print('0')
else:
    for i in range(size):
        list[i] = int(list[i])
    list.sort()
    max = 0
    for j in range(size - 1):
        if max < list[j + 1] - list[j]:
            max = list[j + 1] - list[j]
    print(max)

fcaf52fbd9f437ffd76754350d58091554631704
<mask token>

<mask token>
if size < 2:
    print('0')
else:
    for i in range(size):
        list[i] = int(list[i])
    list.sort()
    max = 0
    for j in range(size - 1):
        if max < list[j + 1] - list[j]:
            max = list[j + 1] - list[j]
    print(max)

list = input().lstrip('[').rstrip(']').split(',')
size = len(list)
if size < 2:
    print('0')
else:
    for i in range(size):
        list[i] = int(list[i])
    list.sort()
    max = 0
    for j in range(size - 1):
        if max < list[j + 1] - list[j]:
            max = list[j + 1] - list[j]
    print(max)
