| 시간 제한 | 메모리 제한 | 제출 | 정답 | 맞힌 사람 | 정답 비율 |
|---|---|---|---|---|---|
| 3 초 | 256 MB | 74 | 32 | 29 | 46.774% |
Ali-Amir wrote N numbers in a row. A row is called beautiful if any two of the neighbour numbers in the row have got the same amount of ones in binary or ternary notations.
Ali-Amir wants to count the number of ways the all given numbers can be written in a beautiful row.
The first line of input file contains integer N (2 ≤ N ≤ 20). The next line contains N non-negative integers not exceeding 109 each.
Output the number of ways the all given numbers can be placed in a beautiful row.
3 5 1 6
2
In the sample 5 = 123 and 1 = 13, 5 = 1012 and 6 = 1102, thus rows 1 5 6 and 6 5 1 are beautiful.