atcoder#AGC012C. [AGC012C] Tautonym Puzzle
[AGC012C] Tautonym Puzzle
Score : points
Problem Statement
We will call a string good if it satisfies the following condition:
- Condition: can be represented as a concatenation of two copies of another string of length at least .
For example, aa
and bubobubo
are good; an empty string, a
, abcabcabc
and abba
are not good.
Eagle and Owl created a puzzle on good strings. Find one string that satisfies the following conditions. It can be proved that such a string always exists under the constraints in this problem.
- Each character of is one of the characters represented by the integers through .
- Among the subsequences of , exactly are good strings.
Constraints
Input
Input is given from Standard Input in the following format:
Output
In the first line, print , the length of . In the second line, print the elements in in order, with spaces in between. Any string that satisfies the above conditions will be accepted.
7
4
1 1 1 1
There are two good strings that appear as subsequences of : and . There are six occurrences of and one occurrence of , for a total of seven.
299
23
32 11 11 73 45 8 11 83 83 8 45 32 32 10 100 73 32 83 45 73 32 11 10