It takes 6 days for a boat to travel from city A to city B, and 9 days to travel from city B to city A. Now, if a raft with no power is placed from city A, how many days does it take to float to city B?
一条船从A城到B城要行6天，而从B城到A城要行9天，现在从A城放一个无动力的木筏，它飘到B城需要多少天．
<gadget id="calculator">6 + 9</gadget>
<output>15</output>

<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<gadget id="calculator">6 + 30</gadget>
<output>36</output>

<result>36</result>