code: public static int maxLetterValue(final int numberOfLetters) {
          int v = 1;
          for (int i = 1; i < numberOfLetters; i++) {
              v *= i%2==0 ? 2 : 5;
          }
          return v;
      }
docs: Given an array of letters, returns the value of the highest letter.
  @param numberOfLetters
  @return value of highest