Limits 2s, 512 MB

The Prothom Alo newspaper sometimes publishes Sudoku for interested readers to solve. Later the solutions are also published. One day, Prothom Alo Editor Matiur Rahman thought, as everything is becoming digital, there should also be a digital version of Sudoku. Then readers will be able to submit the solution on the newspaper website. He assigned Munir Hasan for that job. Now Munir Hasan is a very busy person, he cannot possibly manage to do it himself. Besides, he have been away from programming for a long while. So he appointed a web developer for the task. Within a month the web developer implemented the system. But he was unable to write the program to check whether the Sudoku solution was correct. While being charged by Munir Hasan about that matter, he said, “Sir, I don’t know any logic”. Anyway, now your task is to rescue Munir Hasan from this situation.

A Sudoku consists of a 9×99 \times 9 board (with a total of 81 cells). Initially some cells are filled with a number between 1 and 9. The remaining empty cells are to be filled with numbers ranging from 1 to 9. This should be done in such a way that, no row have the same number more than once and no column have the same number more than once. Each of the nine squares of size 3×33 \times 3 in that 9×99 \times 9 board can also have any number from 1 to 9 only once.


A 9×99 \times 9 Sudoku board where each cell is filled with a number between 1 to 9.


Print Congratulations! If the Sudoku solution is correct. Otherwise print Oh No!


Oh No!