A person was born on February 29, 1792 and died on May 20, 1861. How many times did he have his birthday?
某人生于1792年2月29日，死于1861年5月20日，他一生过了多少次生日？
<gadget id="calculator">1_861 - 1_792 - 1</gadget>
<output>68</output>

<gadget id="calculator">68 / 4</gadget>
<output>17</output>

<gadget id="calculator">17 - 1</gadget>
<output>16</output>

<result>16</result>