Introduce a variable 
which is +1 if the element is on the first chip,
and -1 if it is on the second. Introduce a connectivity matrix 
if i and j are connected, 0 otherwise.
The penalty for connections between chips is
We want roughly the same number of elements in chip 1 
and chip 2
, so we want to make 
as close as
possible to zero. Can do this by adding a penalty term to the cost function
The problem now looks like an Ising spin glass! As we might expect, SA works well for this problem.