There are 22 people on the playground, 9 girls are skipping rope, and 13 boys are skipping rope. How many people are there between the boys skipping rope and the girls skipping rope?
操场上有22个人，有9名女生在跳绳，13名男生在跳绳，跳绳的男生和跳绳女生相差多少人？
<gadget id="calculator">13 - 9</gadget>
<output>4</output>

<result>4</result>