TASK DEFINITION: In this task you will be given a string and you should find the longest substring that is a palindrome. A palindrome is a string that is the same backwards as it is forwards. If the shortest possible palindrome is length 1 you should return the first character.
PROBLEM: gxxxcccggxggccc

SOLUTION: cccggxggccc

PROBLEM: vmmtvvttmvmvttv

SOLUTION: tvvt

PROBLEM: wywwnnnnynwn

SOLUTION:
nnnn