We have a matrix of n*n. Entries are only 0 or 1. Now we need to come up with some matching (vertical or horizontal) for 1's such that 2 1's can be matched. No 0's can be converted to 1 or vice versa. Also, a 1 can be matched to only a single 1, in simple words we cannot a single 1 to two or more 1. We need to print Yes if there's a matching exist such that all 1's are paired or No if not. If Yes, then print all the matching as well. Print any solution if there are multiple matching for a case. Example- Input 4 0011 1110 1110 1111

Output Yes (1,3)(1,4) (2,1)(3,1) (2,2)(3,2) (2,3)(3,3) (4,1)(4,2) (4,3)(4,4)

For n<=200. This can be done by Maximum Bipartite Matching. But can't really do it.