//
// function to decide whether string is a palindrome, ignoring case
// and non-letters
// 

def isPalindrome(s:String) : Boolean = {
  val lc = s.toLowerCase
  //println("DBG lc "+lc)
  val letters = lc.filter(x => x.isLetter)
  //println("DBG letters "+letters)
  //println("DBG " + letters.take(letters.length/2))
  //println("DBG " + letters.takeRight(letters.length/2))
  //println("DBG " + letters.takeRight(letters.length/2).reverse)
  letters == letters.reverse
}