message: Update unique-word-abbreviation.cpp
diff: @@ -21,6 +21,9 @@ private:
  unordered_map<string, unordered_set<string>> lookup_;
  string abbreviation(const string& word) {
  + if (word.length() <= 2) {
  + return word;
  + }
  return word.front() + to_string(word.length()) + word.back();
  }
  };
  