def clean_utterance(utterance: str) -> str:
    """Clean utterance to make it fit the right length and character set.

    Args:
        utterance: The utterance string.

    Returns:
        The utterance that meets Lex specifications.
    """
    stopwords = ['i', 'to', 'a', 'an', 'the']
    new_utterance = ' '.join([w for w in utterance.split() if w.lower() not in stopwords])
    new_utterance = new_utterance[:100]
    return new_utterance