A suspicious factory has 100 sq. feet of space. It makes bootleg phones and laptops. Phones require 2 hours of labor and cost $12 for each sq. foot of space allocated for phone production (cost of electricity and equipment). Laptops require 3 hours of labor and cost $15 for each sq. foot of space allocated for laptop production. Phones produce a net revenue of $50 per sq. foot while laptops produce a net revenue of $70 per sq. foot. The factory wants to spend at most $5000 and 2000 hours of labor. What is the optimal factory layout to maximize revenue?