Three fund managers invest in several stocks. Manager Zhang bought 66 of them, Manager Wang bought 40 of them, and Manager Li bought 23 of them. Manager Zhang and Manager Wang both bought 17, Manager Wang and Manager Li both bought 13, Manager Li and Manager Zhang both bought 9, and all three of them bought 6. May I ask: How many stocks have these three managers bought in total?
三位基金经理投资若干只股票．张经理买过其中66只，王经理买过其中40只，李经理买过其中23只．张经理和王经理都买过的有17只，王经理和李经理都买过的有13只，李经理和张经理都买过的有9只，三个人都买过的有6只．请问：这三位经理一共买过多少只股票？
<gadget id="calculator">17 + 13 + 9</gadget>
<output>39</output>

<gadget id="calculator">23 - 39</gadget>
<output>-16</output>

<gadget id="calculator">66 + 40 + (-16) + 6</gadget>
<output>96</output>

<result>96</result>