codefights arcade intro task 18
palindromeRearranging https://
palindromeRearranging https://
arrayPacking https://
arrayChange https://
chessKnight https://
add https://
isLucky https://
areSimilar https://
alternatingSums https://
areEquallyStrong https://
extractEachKth https://
sumUpNumbers https://
avoidObstacles https://
buildPalindrome https://