Problems
Palindromic Subsequence
Palindromic Subsequence
A Subsequence is a sequence obtained by deleting zero or more characters in a string. A Palindrome is a string which when read from left to right, reads same as when read from right to left. Given a string, find the longest palindromic subsequence. If there are many answers to it, print the lexicographically smallest.
Input
Consists of several tests, each in a separate line. Maximum length of a line is 1000. Each line contains characters from 'a' to 'z' only.
Output
For each line print the lexicographically smallest longest palindromic subsequence.
Input example #1
aabbaabb computer abzla samhita
Output example #1
aabbaa c aba aha