A piece of iron wire just surrounds a rectangle with a length of 15 cm and a width of 7 cm. What is the length of this wire in cm?
一根铁丝刚好围成一个长15厘米、宽7厘米的长方形，这根铁丝长多少厘米．
<gadget id="calculator">15 + 7</gadget>
<output>22</output>

<gadget id="calculator">22 * 2</gadget>
<output>44</output>

<result>44</result>