Mingming's father went on a business trip for 5 consecutive days in March this year. It is known that the sum of the dates of these 5 days is 20. What is the date when Mingming's father arrived home.
明明的爸爸今年3月份连续出差了5天，已知这5天的日期之和是20，明明的爸爸是多少号到家的．
<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">4 + 1 + 1</gadget>
<output>6</output>

<result>6</result>