class Solution {
fun isPalindrome(s: String): Boolean {
val sList = s.lowercase().toList().filter{it in 'a'..'z' || it in '0'..'9'}
println("$sList")
val n = sList.size
for(i in 0 until (n/2)){
if(sList[i] != sList[n - i - 1]) return false
}
return true
}
}