Xiao Qian and Xiao Kun are a pair of twins, Xiao Qian is 3 years younger than Dawei, Xiao Kun is 2 years younger than Lu Fei, how much younger is Dawei than Lu Fei?
萧乾和萧坤是一对双胞胎，萧乾比大伟大3岁，萧坤比陆飞小2岁，则大伟比陆飞小多少岁．
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<result>5</result>