There are 10 planes parked at the airport. After the first plane takes off, one plane takes off every 4 minutes. After each plane takes off, one plane lands at the airport. After that, one plane flies back to land every 6 minutes. The planes at the airport take off after the original 10 planes at an interval of 4 minutes. After the first plane takes off, how long does it take before there are no planes staying at the airport?
机场停着10架飞机，第一架飞机起飞后，每隔4分钟有一架飞机起飞，在每一架飞机起飞后2分钟，有一架飞机在机场降落，以后每隔6分钟飞回一架降落在机场的飞机，又依次相隔4分钟，在原有的10架飞机后起飞，问从第一架飞机起飞后，经过多少时间机场上才没有飞机停留？
<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">9 - 1 - (1/3)</gadget>
<output>23/3 = around 7.666667</output>

<gadget id="calculator">1 + (23/3)</gadget>
<output>26/3 = around 8.666667</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/4) - (1/6)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(26/3) / (1/12)</gadget>
<output>104</output>

<gadget id="calculator">104 + 4</gadget>
<output>108</output>

<result>108</result>