MINIMAX problem corner cases??

Code MINIMAX :- I have tried many test cases of my own and its passing all of them !I dont know why a wrong answer is coming !
Here is the code:-
Algorith is straight forward calculate max(min(all rows))=max,min(max(all columns))=min and calculate first occurance of both and then start counting the number of changes in all rows and columns and Display the minimum answer!!

https://www.codechef.com/viewsolution/15516899

Can anybody provide me with corner cases of this problem?

//