A person goes to the cafeteria to buy rice. There are 3 staple foods and 5 non-staple foods. He buys 1 staple food and 1 non-staple food. How many different ways are there in total?
某人到食堂去买饭，主食有3种，副食有5种，他主食和副食各买1种，共有多少种不同的买法？
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<result>15</result>