Trust Bank loans Corner Bookstore $30,000 on July 1, and receives a security interest in Corner Bookstore`s inventory. Trust Bank files a Financing Statement in the proper courthouse on July 7. On July 3, Corner Bookstore borrows $15,000 from Martha Stevens. Martha also takes a security interest on Corner Bookstore`s inventory. She files her financing statement on July 6. Which security agreement has priority? Why? Please explain in detail.