Six children of different ages, the oldest is 12 years old and the youngest is 3 years old. Among these children are four boys and two girls. The oldest boy is 5 years older than the youngest girl, and the oldest girl is 5 years older than the youngest boy. years old, so how old are the two girls?
六个年龄互不相同的孩子，最大12岁，最小3岁，这些孩子中有四个男孩和两个女孩，其中最大的男孩比最小的女孩大5岁，最大的女孩比最小的男孩大5岁，那么两个女孩相差多少岁．
<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">12 - 5</gadget>
<output>7</output>

<gadget id="calculator">8 - 7</gadget>
<output>1</output>

<result>1</result>