#целые числа без повторов. Надо преобразовать в строку.
# [1,4,5,2,3,9,8,11,0] => "0-5,8-9,11"

input = [0, 2, 4, 5, 6, 8, 9, 11, 12, 14, 16, 17, 18, 19, 24, 25, 28, 29]

x = str(input[0])
counter = -1
prev = 45675765
next = 69696969

last_index = len(input) - 1
last_element = input[last_index]

for element in input:
    counter = counter + 1
    prev = counter - 1
    next = counter + 1

    if element == input[0]:
        continue

    if element == last_element and element - 1 == input[prev]:
        x = x + '-' + str(element)
        continue
    if element == last_element and element - 1 != input[prev]:
        x = x + ',' + str(element)
        continue

    if element - 1 == input[prev] and element + 1 != input[next]:
        x = x + '-' + str(element)

    if element - 1 == input[prev]:
        continue

    else:
        x = x + ',' + str(element)

print(x)