def sentence_to_spans(tokenized_sentence: list[str]) -> dict[str, int]:
    span_to_token_id_ = dict()
    start = 0
    for index, token_ in enumerate(tokenized_sentence):
        span_to_token_id_[f"{start + index}-{start + index + len(token_)}"] = index
        start += len(token_)
    return span_to_token_id_