ДЗ. Задание 11

def get_intervals(numbers):
    intervals = []
    current = [numbers[0], numbers[0]]

    for number in numbers[1:]:
        if number - current[1] != 1:
            intervals.append(current)
            current = [number, number]

        current[1] = number

    intervals.append(current)
    return intervals


def to_str(interval):
    a, b = interval

    if b - a == 1: return "{},{}".format(a, b)
    if b - a > 1: return "{}-{}".format(a, b)
    return str(a)


numbers = list(map(int, input().split()))
intervals = get_intervals(numbers)
print(*map(to_str, intervals), sep=",")