Xiaohong's father went on a business trip on May 1 and came back on May 3. How many days did Xiaohong's father travel in total?
小红的爸爸5月1日出差，5月3日回来，小红的爸爸一共出差了多少天天．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<result>2</result>