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:
nqnnffnnnfnq
answer:
nnffnn


question:
rprrrprzppzr
answer:
rprrrpr


question:
nrrrrrnrrrrr
answer:

rrrrrnrrrrr