var words = ARGF.grep(/^[[:alpha:]]+\z/);

var dials = words.group_by {
    .tr('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
        '2223334445556667777888999922233344455566677778889999');
}

var textonyms = dials.grep_v { .len > 1 };

say <<-END;
    There are #{words.len} words which can be represented by the digit key mapping.
    They require #{dials.len} digit combinations to represent them.
    #{textonyms.len} digit combinations represent Textonyms.
    END

say "Top 5 in ambiguity:";
say textonyms.sort_by { |_,v| -v.len }.first(5).join("\n");

say "\nTop 5 in length:";
say textonyms.sort_by { |k,_| -k.len }.first(5).join("\n");