MCNP 6 - Doubts about cells

Question

I'm trying to insert a cylinder in the MCNP 6 code. I believe I defined the surfaces and planes correctly. What could be wrong?

Surfaces:

520 cz  435  1

5020 px  435

6020 px  450

Cells:
81     5  -1.2250E-3       (-520 5020 -6020)
99    5  -1.2250E-3              -3552 1050 -110
                                 (110:-1050:-33:33:29:-35:36)                            
                                 (110:-1050:-30:34:-35:36)
                                 (110:-109:-29:30:-35:36)
                                 (109:-1050:-29:30:31:-35)
                                 (109:-1050:-29:30:-32:36)
                                 (110:-1050:-33:29:-35:36)
                                 (520:-5020:6020)

What could be wrong?