2-3. Given an array of integers, write a function to calculate the sum of the elements if it is a palindrome array. If it is not a palindrome array, your function must return -2. Your function must call separate functions to check whether or not the array is a palindrome and to calculate the sum of its elements. If the length is O or negative each function must return-1 or false as its result. Signature: int sum if.a.palindromeCint integersCD, int length) Signature: bool is a.palindromeCint integers,int length) Signature: int sumelementsCint integers, int length)