A said to B: "When my age is your current age, you are only 4 years old." B said to A: "When my age is your current age, you will already be 61 years old." How much is A now? age.
甲对乙说："当我的岁数是你现在的岁数时，你才4岁．"乙对甲说："当我的岁数是你现在的岁数时，你已经61岁了．"现在甲多少岁．
<gadget id="calculator">61 - 4</gadget>
<output>57</output>

<gadget id="calculator">57 / 3</gadget>
<output>19</output>

<gadget id="calculator">19 + 4</gadget>
<output>23</output>

<gadget id="calculator">23 + 19</gadget>
<output>42</output>

<result>42</result>