Mr. Li went to a company to apply for a job. The company had a probationary period for the first 3 months. During the probationary period, the monthly salary was 600 yuan. What is the annual income of Mr. Li in the first year?
李先生到某公司应聘，该公司前3个月是试用期，试用期每月工资600元，试用期结束后的第一个月工资800元，以后每月工资比上一个月多25元．李先生第一个年的年收入是多少元．
<gadget id="calculator">600 * 3</gadget>
<output>1_800</output>

<gadget id="calculator">800 * 9</gadget>
<output>7_200</output>

<gadget id="calculator">1_800 + 7_200 + 25 + 50 + 75 + 100 + 125 + 150 + 175 + 200</gadget>
<output>9_900</output>

<result>9_900</result>