Xiao Ming's father has 4 pairs of leather shoes and 5 suits. How many different ways can his leather shoes and suits be matched?
小明的爸爸有4双皮鞋和5套西服，他的皮鞋和西服有多少种不同搭配方式．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>