New Era Primary School organized the third-grade children to go on an autumn outing and rented 4 buses. Each car has 50 seats, but 13 seats were empty. How many students in the third grade went to the autumn tour?
新时代小学组织三年级小朋友去秋游，共租了4辆大客车．每辆有50个座位，结果有13个座位空着．三年级共有多少名学生去秋游？
<gadget id="calculator">4 * 50</gadget>
<output>200</output>

<gadget id="calculator">200 - 13</gadget>
<output>187</output>

<result>187</result>