Mom has 1 sweater, 1 coat, 1 pair of trousers, and 1 skirt. How many different matching methods are there to make a set of clothes? Please write it out.
妈妈有1件毛衣，1件大衣，一条裤子，一条裙子，要配成一套衣服有多少种不同的搭配方法？请写出来．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>