For a manuscript, it takes 12 days for A to type it alone, and 18 days for B to type it alone. Today, the two of them are working together, but because A has something to do, they took a day off in the middle. How many days will it take to finish this manuscript?
一份稿件，甲单独打需12天完成，乙单独打需18天完成，今两人合打，但由于甲有事，中途走了一天，这份稿件经过多少天才能打完？
<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 - (1/18)</gadget>
<output>17/18 = around 0.944444</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/12) + (1/18)</gadget>
<output>5/36 = around 0.138889</output>

<gadget id="calculator">(17/18) / (5/36)</gadget>
<output>34/5 = around 6.8</output>

<gadget id="calculator">(34/5) + 1</gadget>
<output>39/5 = around 7.8</output>

<result>39/5 = around 7.8</result>