Matrix - Filter by blank in last column

I have a matrix like below:   Room 08/08/2018 15/08/2018 22/08/2018 29/08/2018 05/09/2018 a 1 1     1 b 1 1 1 1 1 c   1 1 1   d 1 1 1 1 1 e 1 1 1    ...