Solve the following linear programming problem with two methods
A company producing A, B, C, D four kinds of specifications of the electronic products, the four kinds of products can be in five different production workshop made separately, the five workshop manufacturing A product need time alone, each workshop can provide the total manufacturing time and each product's profits in the following table:

Product model time needed for A B C D (minutes) workshop 1 workshop 2 workshop 3 workshop 4 workshop 5 5 8-6 3-18000-4-2 3 16000 2, 3, 4, 4, 3, 4-2 14000 15000 singleton profits (20 18 to 24 to 30 yuan) can provide the total time of 20000, the company sales staff to provide information:

(1) the product of A number of sales does not exceed 1500 pieces; (2) the product B sales between 500-900; (3) products sales quantity does not exceed 6000 C;

D (4) products can be sold at least 800 pieces, on this basis, how much can sell how much production, please make a production plan, make the company's total profits for the biggest,

The first: it is concluded that the optimal solution after their input all possible solutions

The second requires the use of a for loop will all possible solution circulation after solving the optimal solution