An entrepreneur needs to sell at least 12 products type A and at least 18 products type B to pay the monthly rent. There are two cities in which the entrepreneur can sell his products. Each day that he spends in city 1, he sells 2 products A and 2 products B. Each day that he spends in city 2, he sells 1 product A and 3 products B. Formulate an LP to help entrepreneur meet her requirements while spending as little time as possible in the cities.