Description

Physicists study atoms hidden in a ``black box". So as to get information on the position of atoms in the box, they cast a laser beam through gates and look at where light gets out from the box. As a computer scientist you are (kindly) requested to interpret the physicists experiments.

Problem

By weighting the box, the physicists already managed to count how many atoms there are (K = 5) . Besides, they adopt a grid model. First, the box is quite simple: this is a flat, N x N box (N = 8) , with 32 = 4 * N gates, which are numbered as shown above. Additionally, following the famous ``no border principle" and a loose application of Pauli exclusion principle, the physicists restrict the available positions to the central 36 = (N - 2)² positions, and they assume that no two atoms occupy the same position. Besides, in the grid model, light is also quite simple:

• Light travels at infinite speed in either of the fourth directions, east, north, west or south. For instance, if the beam enters the box from the west, then it travels eastward.

Input

Input is a log of experiments performed over a given box. The first line is an integer e (0 < e<=32) . Integer e is the number of experiments performed. Then, come e lines, each line being made of two integers. The first integer i is a gate number expressing that the beam enters the box at gate i . The second integer o is either a gate number, expressing that the beam leaves the box at gate o , or the integer `-1', expressing that the beam is absorbed.

Output

If the atom positions can be deduced from the experiments, then your program should output an ascii representation of the box, as N lines of N characters, with atoms being shown as `+' and empty positionsas `-' -- See the first example below. Otherwise, your program should output `NO' on a single line. Notice that `NO' is the correct answer in several situations. More specifically, the experiments may be contradictory (there does not exist a repartition of atoms compatible with the experiments) or non-concluding (there exist several repartitions of atoms compatible with the experiments).

7
0 29
27 -1
21 -1
10 10
3 -1
16 7
6 12

--------
---++---
--------
-+-+----
--------
-----+--
--------
--------

Hint

Observe that this output describes the box shown in the introduction.

If input is:

10

0 23

1 28

7 8

20 -1

19 25

10 16

2 31

4 5

12 -1

29 -1

Then, correct output is:

NO

Source

Southwestern Europe 2005