## Task Description

We define a palindrome as a sequence of at least one integer that reads the same either forward or backward. For example `1 3 5 3 1`

and `1 2 2 1`

are both palindromes. To the extreme case `1`

is also a palindrome. We also define a double palindrome as the concatenation of two palindromes. For example `1 3 5 3 1 1 2 2 1`

is a double palindrome. To the extreme case `1 3 5 3 1 1`

is also a double palindromes. Now given a sequence of at least two integers, please find the longest double palindrome. If there are multiple longest double palindromes, print the one that appears ** last **.

## Limits

The number of integers in the given sequence is no more than 100.

## Input Format

There is one line in the input. The first line has the integers from which we want to find the longest double palindrome.

## Output Format

There is one lines in the output. The first line has all the integers of the longest double palindrome. number of ways as in the description.

## Sample Input

`7 1 3 5 3 1 1`

## Sample Output

`1 3 5 3 1 1`

## Special Thanks

感謝 B05902052 劉家維 同學增加測資