JP Inc. produces two types of printers, regular and high-speed. Let R be the number of regular printers produced per month and H be the number of high-speed printers produced per month. Each regular printer uses 2 units of plastic, and each high-speed printer uses 1 unit of plastic. JP is committed to using at least 5,000 units of plastic per month. A machine is needed to manufacture the printers. Each regular printer requires 5 units of time in this machine, and each high-speed printer requires 3 units of time. The total time available in this machine per month is at most 15,000 units. The profit of each regular printer is 50 and the profit of each high-speed printer is 100. How many corner points are there in the feasible region?