A farmer is planting two types of trees: apple trees and peach trees. Each apple tree requires 15 square feet of space and costs $25. Each peach tree requires 20 square feet of space and costs $30. The farmer has a total of 300 square feet available for planting and a budget of $340. If the farmer wants to plant at least 12 trees in total, what is the maximum number of peach trees the farmer can plant?