In (19+1.9*(2.9-□))/0.38=55, what is the number to be filled in □.
在(19+1.9*(2.9-□))/0.38=55中，□里要填的数是多少．
<gadget id="calculator">19 / 0.38</gadget>
<output>50</output>

<gadget id="calculator">2.9 / 0.38</gadget>
<output>7.631579</output>

<gadget id="calculator">1.9 * 7.631579</gadget>
<output>14.5</output>

<gadget id="calculator">14.5 - 55</gadget>
<output>-40.5</output>

<gadget id="calculator">50 + (-40.5)</gadget>
<output>9.5</output>

<gadget id="calculator">1 / 0.38</gadget>
<output>2.631579</output>

<gadget id="calculator">1.9 * 2.631579</gadget>
<output>5</output>

<gadget id="calculator">9.5 / 5</gadget>
<output>1.9</output>

<result>1.9</result>