Design and analysis of algorithm

A sequence is a palindrome if it reads the same whether we read it from left to right or right to left. For instance, A C G G G G C A is a palindrome.

A G T C M C T G A is a palindrome of length 9.

Problem:

Here  is a set of characters.

S A G E S R A D A R U K M Y G Y M D T O P S P O T B S

1. Find the longest palindrome or sequence in the set. 

2. Write your own algorithm to explain how to arrive to the solution. Illustrate your answer. Your algorithm should work with any set of characters.