A cylindrical bucket without a lid, measured from the inside, has a base diameter of 40 cm and a height of 50 cm. Use this bucket to fill water to water the flowers, with an average of 0.4 liters of water per flower. How many flowers can this bucket of water water at most?
一个圆柱形状的无盖水桶，从里面量，底面直径40厘米，高50厘米．用这个水桶装满水去浇花，平均每棵花用水0.4升．这桶水最多可以浇多少棵花？
<gadget id="calculator">40 / 10 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">50 / 10 / 0.4</gadget>
<output>12.5</output>

<gadget id="calculator">3.14 * 4 * 12.5</gadget>
<output>157</output>

<result>157</result>