There are 35 big and small monkeys, and they go to pick peaches together. When the monkey king is not around, a big monkey can pick 15 kilograms an hour, and a small monkey can pick 11 kilograms an hour. When the monkey king was present to supervise, each monkey, regardless of its size, could pick 12 kilograms more per hour. One day, after picking for 8 hours, only the first hour and the last hour were supervised by the Monkey King. As a result, a total of 4400 kilograms of peaches were picked. How many monkeys are there in this group of monkeys?
大、小猴子共35只，它们一起去采摘水蜜桃．猴王不在的时候，一只大猴子一小时可采摘15千克，一只小猴子一小时可采摘11千克．猴王在场监督的时候，每只猴子不论大小每小时都可以多采摘12千克．一天，采摘了8小时，其中只有第一小时和最后一小时有猴王在场监督，结果共采摘4400千克水蜜桃．在这个猴群中，共有小猴子几只？
<gadget id="calculator">35 * 15</gadget>
<output>525</output>

<gadget id="calculator">35 * 12 * 2</gadget>
<output>840</output>

<gadget id="calculator">4_400 - 840</gadget>
<output>3_560</output>

<gadget id="calculator">3_560 / 8</gadget>
<output>445</output>

<gadget id="calculator">525 - 445</gadget>
<output>80</output>

<gadget id="calculator">15 - 11</gadget>
<output>4</output>

<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<result>20</result>