def stem(self, word):
lowered = word.lower()<EOL>if lowered[-<NUM_LIT:3>:] == '<STR_LIT>' and lowered[-<NUM_LIT:4>:-<NUM_LIT:3>] not in {'<STR_LIT:e>', '<STR_LIT:a>'}:<EOL><INDENT>return word[:-<NUM_LIT:3>] + ('<STR_LIT:Y>' if word[-<NUM_LIT:1>:].isupper() else '<STR_LIT:y>')<EOL><DEDENT>if lowered[-<NUM_LIT:2>:] == '<STR_LIT>' and lowered[-<NUM_LIT:3>:-<NUM_LIT:2>] not in {'<STR_LIT:a>', '<STR_LIT:e>', '<STR_LIT:o>'}:<EOL><INDENT>return word[:-<NUM_LIT:1>]<EOL><DEDENT>if lowered[-<NUM_LIT:1>:] == '<STR_LIT:s>' and lowered[-<NUM_LIT:2>:-<NUM_LIT:1>] not in {'<STR_LIT:u>', '<STR_LIT:s>'}:<EOL><INDENT>return word[:-<NUM_LIT:1>]<EOL><DEDENT>return word<EOL>
Return the S-stemmed form of a word.

        Parameters
        ----------
        word : str
            The word to stem

        Returns
        -------
        str
            Word stem

        Examples
        --------
        >>> stmr = SStemmer()
        >>> stmr.stem('summaries')
        'summary'
        >>> stmr.stem('summary')
        'summary'
        >>> stmr.stem('towers')
        'tower'
        >>> stmr.stem('reading')
        'reading'
        >>> stmr.stem('census')
        'census'