code: private String cleanup(String word) {
          int last = word.length();
          String temp = "";
          for (int i = 0; i < last; i++) {
              if ((word.charAt(i) >= 'a') & (word.charAt(i) <= 'z')) {
                  temp += word.charAt(i);
              }
          }
          return temp;
      }
docs: Remove all non letter or digit characters from word