There is a colored ribbon, folded in half, folded in half, and folded in half again, the length of each piece is measured to be 5 cm. How long is the original ribbon?
有一根彩带，对折、对折、再对折，量得每段长5厘米．原来的彩带长多少．
<gadget id="calculator">5 * 2 * 2 * 2</gadget>
<output>40</output>

<result>40</result>