Xiao Ming went to grandma's house during the summer vacation. He set off on July 18 and came back on August 6. How many days did he stay?
小明暑假里去奶奶家，7月18日出发，8月6日回来，共住了多少天．
<gadget id="calculator">31 - 18</gadget>
<output>13</output>

<gadget id="calculator">13 + 1</gadget>
<output>14</output>

<gadget id="calculator">14 + 5</gadget>
<output>19</output>

<result>19</result>