There are 60 people in a class. They wear white or black jackets and black or blue pants. Among them, 12 people wear white jackets and blue pants, 34 people wear black pants, and 29 people wear black jackets. Then there are those who wear black jackets and black pants. how many people.
某班有60人，他们着装白色或黑色上衣，黑色或蓝色裤子，其中有12人穿白色上衣蓝裤子，有34人穿黑裤子，29人穿黑上衣，那么穿黑上衣黑裤子的有多少人．
<gadget id="calculator">60 - 34</gadget>
<output>26</output>

<gadget id="calculator">26 - 12</gadget>
<output>14</output>

<gadget id="calculator">29 - 14</gadget>
<output>15</output>

<result>15</result>