When Xiaohong grows up to her mother's current age, her mother is 77 years old. When her mother is Xiaohong's current age, Xiaohong is 2 years old. Find Xiaohong's current age.
小红长到妈妈今年的年龄时，妈妈77岁，当妈妈是小红今年的年龄时，小红2岁，求小红今年的年龄．
<gadget id="calculator">77 - 2</gadget>
<output>75</output>

<gadget id="calculator">1 + 1 + 1</gadget>
<output>3</output>

<gadget id="calculator">75 / 3</gadget>
<output>25</output>

<gadget id="calculator">25 + 2</gadget>
<output>27</output>

<result>27</result>