Longest Possible Chunked Palindrome

Given a string, the task is to return the length of its longest possible chunked palindrome. It means a palindrome formed by substrings. For better understanding, look at the examples below.


"ghiabcdefhelloadamhelloabcdefghi" should return 7. The palindrome is (ghi)(abcdef)(hello)(adam)(hello)(abcdef)(ghi).

"merchant" should return 1. The palindrome is (merchant).

Contributed by Berkan Teber