public class LoopPalindromes
{
   public static void main(String[] args)
   {
      String sentence1 = "Madam, I'm Adam!";      
      System.out.println(sentence1);
      System.out.println("Palindrome: " + isPalindrome(sentence1));
      String sentence2 = "Sir, I'm Eve!";      
      System.out.println(sentence2);
      System.out.println("Palindrome: " + isPalindrome(sentence2));
   }

   /**
      Tests whether a text is a palindrome.
      @param text a string that is being checked
      @return true if text is a palindrome, false otherwise
   */
   public static boolean isPalindrome(String text)
   {
      int start = 0;
      int end = text.length() - 1;
      while (start < end)
      {
         char first = Character.toLowerCase(text.charAt(start));
         char last = Character.toLowerCase(text.charAt(end));
         if (Character.isLetter(first) && Character.isLetter(last))
         {
            // Both are letters.
            if (first == last)
            {
               start++;
               end--;
            }
            else
            {
               return false;
            }
         }
         if (!Character.isLetter(last)) { end--; }
         if (!Character.isLetter(first)) { start++; }
      }
      return true;
   }
}