from typing import NamedTuple, List

class Range(NamedTuple):
    start: int
    length: int

def from_indexes(indexes: List[int]) -> List[Range]:
    ranges = []
    curr_range_start = 0
    curr_range_len = 0

    last_index = -1

    for index in sorted(indexes):
        if index == curr_range_start + curr_range_len:
            curr_range_len += 1
        else:
            if curr_range_len > 0:
                ranges.append(Range(
                    start = curr_range_start,
                    length = curr_range_len))
            curr_range_start = index
            curr_range_len = 1

    if curr_range_len > 0:
        ranges.append(Range(
            start = curr_range_start,
            length = curr_range_len))

    return ranges