I was giving this "homework" from my co-worker and I've gotten an answer and he says that it was wrong.. I'm not sure how to put pictures

His Question:
There are 6 lights

Light 1 is all the time except when light 4 is on
Light 4 is on only when lights 1, 5, 6 are off
Light 5 is off only when light 2 is on
Light 6 is on only when light 3 is on
Light 2 comes on with a switch which also shuts off Light 3


---------SWITCH-------Light 2 ---- light 4------------
| | |
| | |
| ----Light 1 ---- light3 --- light5 -- light6------
| |
-----------------------------------------------------------

This is what I came up with.. as I said sorry but I can't figure out a way to
Put pictures on here.. best I could come up with

Are you allowed the use of other devices or just the one switch?