A company wants to purchase two types of lightbulbs, CFL (compact fluorescent) and LED (light emitting diode). The cost of each CFL bulb is $2, and the cost of each LED bulb is $20. The company must purchase a total of 800 lightbulbs, must spend at most $5,000 on the lightbulbs, and wants to purchase as many LED bulbs as possible. Let L represent the number of LED lightbulbs purchased, and C represent the number of CFL lightbulbs purchased.