Palindromize Array(keteki)

Given an array A, a "palindrome array" is an array which reads the same whether you read the elements from first to last or from last to first. For example: 1 2 2 1 is a palindrome array, while 1 2 3 is not. You need to convert an array to a palindrome array by adding numbers to the elements in the array. To add the numbers you can only use the numbers of the array A itself, and each number nee