Xiaohua was born on March 1, 2000, how many birthdays did he have until April 2, 2013?
小华于2000年3月1日出生，到2013年4月2日他一共过了多少个生日．
<gadget id="calculator">2_013 - 2_000</gadget>
<output>13</output>

<result>13</result>