An oil drum with a bottom radius of 0.5 meters rolls inside the walls on both sides. The distance between the two walls is 26.12 meters. How many times does it take for the oil drum to roll from one side to the other?
底面半径为0.5米的油桶，在两侧墙内滚动，两墙之间的距离是26.12米，油桶从这侧滚到那侧要滚多少圈．
<gadget id="calculator">0.5 * 2</gadget>
<output>1</output>

<gadget id="calculator">26.12 - 1</gadget>
<output>25.12</output>

<gadget id="calculator">3.14 * 2 * 0.5</gadget>
<output>3.14</output>

<gadget id="calculator">25.12 / 3.14</gadget>
<output>8</output>

<result>8</result>