There were originally 500 passengers on the Dream passenger ship. After arriving at the port, 164 people disembarked and another 128 people boarded. How many passengers are on the passenger ship now?
梦想号客轮原有乘客500人，到达港口后有164人离船，另有128人上船．现在客轮上有多少乘客？
<gadget id="calculator">500 - 164</gadget>
<output>336</output>

<gadget id="calculator">336 + 128</gadget>
<output>464</output>

<result>464</result>