from typing import Counter
from functools import reduce


def merge_raw_vocabs(*raw_vocabs: Counter) -> Counter:
    """
    Merges multiple raw vocabularies into a single one.

    :param raw_vocabs: Raw vocabularies.
    :return: Merged raw vocabulary.
    """
    raw_vocab = reduce(lambda c1, c2: c1 + c2, raw_vocabs)
    return raw_vocab