cylindrical glass tank, its lateral expansion is a rectangle with a side length of 6.28 decimeters. Pour 15.7 cubic decimeters of water into this glass jar, how many decimeters will the water surface be from the edge of the jar?
一个圆柱形的玻璃缸，它的侧面展开是一个边长为6.28分米的长方形．把15.7立方分米的水倒入这个玻璃缸内，水面离缸沿还有多少分米？
<gadget id="calculator">6.28 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">15.7 / 3.14</gadget>
<output>5</output>

<gadget id="calculator">6.28 - 5</gadget>
<output>1.28</output>

<result>1.28</result>