The teacher bought some gifts for Thao, Nhi, Duc and Hai. Each student will get one gift among a teddy bear, a bunch of flowers, a robot and a book, but he did not know how to divide the gifts. He asked students what kind of gifts they don't like. They answered the following:
• Hai: I don't like the bunch of flowers.
• Duc: I don't like the book.
• Nhi: I don't like the robot.
• Thao: I don't like the teddy bear.
How many ways does the teacher have to give the gifts to students?