A block of ice loses half of its weight every hour, and its weight is 0.5 kg after eight hours. What is the weight of this block of ice at the beginning?
一块冰，每小时失去其重量的一半，八小时后其重量为0.5千克，那么一开始这块冰的重量是多少千克．
<gadget id="calculator">0.5 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2</gadget>
<output>128</output>

<result>128</result>