Originally 426 people visited the exhibition hall, 121 people left, and 98 people came again. How many people have visited the exhibition hall?
展览馆原有426人参观，走了121人，又来了98人，展览馆现有多少人参观．
<gadget id="calculator">426 - 121</gadget>
<output>305</output>

<gadget id="calculator">305 + 98</gadget>
<output>403</output>

<result>403</result>