We have a coop that is 4' wide x 8' long x 5' high with a run that is 8'wide x 16' long x 5' high.. We are wanting to make it bigger by building an additional coop that will be 12' longer x 4' wide x 5' high with an additional 12' wider x 8' wide x 5'high.. Total coop will be 20' long x 4' wide x 5' high & the run will be a 20' wide by 16' long x 5' high... How many chickens should we have to where they are comfortable & safe?? Tricky with the math I know but want to make sure we don't over crowd..