The Monkey King called a meeting of the monkeys. During the roll call, he found that the number of absentees was the number of attendees (1/7). He was very angry. Just as he was about to get angry, two more monkeys came. At this time, the number of absences was the number of attendants (1/8). How many monkeys are there in total?
猴王召集猴子们开会．点名时，发现缺席只数是出席只数的(1/7)，他很生气，刚要发火，又跑来了2只猴子，这时缺席只数是出席只数的(1/8)，这群猴子共有多少只？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/8) - (1/9)</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">2 / (1/72)</gadget>
<output>144</output>

<result>144</result>