you can get the problem statement from here.
we have to calculate length of longest palindromic suffix of given string and then concatenate the given string with the part other than the longest palindromic suffix.
As we already know how to generate longest Proper Prefix of string such that it is also it’s suffix (used in KMP algorithm), we have calculate the longest proper pefix of a new string NS.
NS = str(reversed(S)) + S
the longest proper prefix of NS which is also a suffix of NS is our palindromic suffix of S.