There is an iron wire 60 cm long, use it to form a rectangular frame with a length of 15 cm and a width of 12 cm, how much wire is left?
有一根长60厘米的铁丝，用它围成一个长15厘米、宽12厘米的长方形框架，还剩下多少铁丝？
<gadget id="calculator">15 + 12</gadget>
<output>27</output>

<gadget id="calculator">27 * 2</gadget>
<output>54</output>

<gadget id="calculator">60 - 54</gadget>
<output>6</output>

<result>6</result>