#2075. [COCI 2023/2024 #1] Sudoku

[COCI 2023/2024 #1] Sudoku

[COCI 2023/2024 #1] Sudoku

Sudoku is a logic - based, combinatorial number - placement puzzle. The objective is to fill a 9×99\times 9 grid with digits from 1 to 9 in such a way that the following statements hold:

  1. Each row contains exactly one occurrence of each digit from 1 to 9.
  2. Each column contains exactly one occurrence of each digit from 1 to 9.
  3. Each of the nine 3×3 subgrids contains exactly one occurrence of each digit from 1 to 9.

For a given not yet finished sudoku grid, determine if there is a mistake in it.

Note: It is not necessary to check whether the sudoku grid is solvable.

Input

The input describes the sudoku grid.

The characters '|', '-' and '+' frame the 3×33\times 3 subgrids.

The character '.' represents an empty cell.

All the other characters in the input will be digits from '1' to '9'.

See the examples for clarification.

Output

Output the word GREŠKA if there is a mistake in the sudoku board. Otherwise, output the word OK.

Examples

+---+---+---+
|52.|...|.81|
|.39|58.|...|
|.8.|.9.|...|
+---+---+---+
|24.|...|1.3|
|1..|43.|86.|
|.63|..7|.24|
+---+---+---+
|...|1.9|35.|
|..8|.74|6..|
|31.|86.|7.9|
+---+---+---+
OK
+---+---+---+
|3..|6..|..4|
|4.9|8.1|..7|
|..7|.49|6..|
+---+---+---+
|946|157|8.2|
|.2.|3..|745|
|.7.|28.|...|
+---+---+---+
|...|4..|..5|
|8.5|.6.|.2.|
|734|..8|5..|
+---+---+---+
GRESKA
+---+---+---+
|5..|98.|67.|
|6..|...|.31|
|.2.|613|.4.|
+---+---+---+
|.96|8.2|1.7|
|.28|..5|.9.|
|7.3|19.|6..|
+---+---+---+
|962|.7.|.1.|
|1.5|...|76.|
|.7.|5..|9..|
+---+---+---+
GRESKA