WHAT ASPECT OF THE PROBLEM WAS MOST DIFFICULT?
Maybe not difficult but applying the constraint on mass 
and relative illumination took most of the time, since 
this was not standard available in the simulation package.

WHAT INSIGHTS (IF ANY) DID YOU GAIN FROM WORKING ON THE PROBLEM? 
Limited because I could spent only little time to solve 
the problem. I think most of insight will arise from seeing 
the other solutions.

ADDITIONAL COMMENTS: 
Looking forward to your discussion of the various solutions 
in Hawaii!