Робота з рядками

Word the champion

Some offer in unknown language is set. We shall name a word in it the champion if it is палиндромом and the quantity of letters in it is maximal. Letters of the alphabet in unknown language are letters of the latin alphabet and the Arabian figures. It is guaranteed, that other symbols, except for blanks and punctuation marks in the offer is not present.


The offer in unknown language.


Number of a word of the champion.

Time limit 0.5 seconds
Memory limit 64 MiB
Input example
Oo, it aaa is not bb.
Output example