instruction:
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.
question:
hhssihiiiii
answer:
iiiii


question:
yyuuuyuueyeuu
answer:
uueyeuu


question:
tsutuuusss
answer:

utu