#P3424. Better security
Better security
Description
Young black-hat hacker Vasya routinely installs key loggers on every computer he can get his hands on. Browsing the logs collected, he sometimes can glance passwords of unaware users.
The IT department of the university where Vasya studies noticed suspicious activity and introduced a new, more secure way to enter passwords. Instead of password input field, window with 9 buttons is displayed. Buttons are arranged into 3 × 3 grid as shown in the table below.
7 | 8 | 9 |
4 | 5 | 6 |
1 | 2 | 3 |
Each button is a square of 100 by 100 pixels. There is no space between buttons. User must enter (digital) password by clicking buttons with a mouse.
To overcome this scheme, Vasya downloaded another cool program: mouse logger. It saves coordinates of clicks in a file, which Vasya is later able to browse. However, a complication has arisen: no information is saved about the position of password window on the screen. Indeed, it might even be partially off screen!
Your program must, given the series of mouse clicks, determine all possible corresponding passwords.
Input
Input file contains number of clicks N followed by integer coordinates x1 y1 x2 y2…xN yN.
Constraints
1 ≤ N ≤ 100, 0 ≤ xi yi ≤ 1000
Output
Output file must contain one line per possible password. Each line must consist of exactly N digits. Lines must be sorted in lexicographical order. If there are no possible combinations, output file must contain the string NONE.
Sample Input 1
2
10 12 110 12
Sample Input 2
2
10 12 750 12
Sample Output 1
12
23
45
56
78
89
Sample Output 2
NONE
Hint
Bold texts appearing in the sample sections are informative and do not form part of the actual data.
Source
Northeastern Europe 2006, Far-Eastern Subregion