Chunzi will travel to Beijing tomorrow. She tore off the 7-day travel calendar and put it in her satchel. It is found that the sum of the dates of these 7 days is exactly 140, what day should it be today? (7-day travel days include departure and return days)
春子明天将去北京旅游．她把旅游7天的日历撕下来放在挎包里．发现这7天日期的和刚好是140，今天应该是几日？(7天旅游天数包括出发和回家的天数)
<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<gadget id="calculator">20 - 3 - 1</gadget>
<output>16</output>

<result>16</result>