Problem A : Palindromic Subsequence
Time Limit: 3 sec
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 one that comes lexicographically earliest.
Constraints
- Maximum length of string is 1000.
- Each string has characters 'a' to 'z' only.
Input Format
Input consists of several strings, each in a separate line.
Input is terminated by EOF.
Output Format
For each line in the input, print the output in a single line.
Sample Input
aabbaabb
computer
abzla
samhita
Sample Output
aabbaa
c
aba
aha
Problem Setters: Vijay S, Rajesh S R
Written for Samhita' 08