Problem K. KINA Is Not Abbreviation

Author:ACM ICPC NEERC 2008 Jury | Georgiy Korneev (idea and original text), Mikhail Dvorkin (final text)   Time limit:2 sec
Input file:kina.in   Memory limit:256 Mb
Output file:kina.out  

Statement

When introducing new terms consisting of several words, it is useful to use abbreviations. An abbreviation is a word that consists of the first letters of several consecutive words.

An abbreviation is called unambiguous if the following two conditions are satisfied:

For example, in the text "A recursive acronym KINA means "KINA is not abbreviation", strings "ARA" and "K" are unambiguous abbreviations, strings "A" and "KINA" are ambiguous abbreviations, and strings "RAA" and "KNA" are not abbreviations.

To introduce an abbreviation in a text, it is placed in parentheses right after the sequence of words it corresponds to. Future occurrences of this sequence of words can be replaced by the abbreviation. In the example text above, introduction of the abbreviation "K" produces the following text: "A recursive acronym KINA (K) means "K is not abbreviation"".

If two occurrences of a sequence of words overlap, only one of them can be replaced by the abbreviation. Words in a sequence are separated by one or more non-alphabetic characters. Comparison of words is case-insensitive. For example, "i18n" is an occurrence of the word sequence "I n".

The effectiveness of an abbreviation is the decrease in the number of letters after introduction of this abbreviation. Only letters are taken into account; spaces, parentheses and all other non-alphabetical characters do not count.

Given a text, find an unambiguous abbreviation with the maximum effectiveness.

Input file format

The input file contains a text with at most 4000 characters. The text contains only characters with ASCII codes 32 (space) to 126 ("~"), 13 (carriage return), and 10 (line feed).

Output file format

If there is no unambiguous abbreviation with positive effectiveness, then the output file should contain the single number 0.

Otherwise, the first line of the output file should contain the effectiveness of the optimal abbreviation. The second line should contain the unambiguous abbreviation itself. If there are multiple unambiguous abbreviations with the maximum effectiveness, output any one of them.

Sample tests

No. Input file (kina.in) Output file (kina.out)
1
This problem name is "KINA is not abbreviation".
Once again: KINA is not abbreviation.
11
NA
2
To be or not to be: that is the question.
0
3
Here is the chorus of the song "Jingle Bells":
Jingle bells, jingle bells,
Jingle all the way;
Oh what fun it is to ride
In a one-horse open sleigh.
16
JB

0.045s 0.011s 15