After subtracting the same number from the numerator and denominator of (71/97), it becomes (2/3), what is the subtracted number?
(71/97)的分子分母减去同一数之后为(2/3)，则减去的数是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * 97</gadget>
<output>194/3 = around 64.666667</output>

<gadget id="calculator">71 - (194/3)</gadget>
<output>19/3 = around 6.333333</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(19/3) / (1/3)</gadget>
<output>19</output>

<result>19</result>