Paint 100 cylindrical iron ventilation pipes. The length of the pipe is 1.8 meters, and the diameter of the nozzle is 1 decimeter. If 0.5 kilograms of paint is used per square meter, how many kilograms of paint should be used at least?
油漆100个圆柱形铁皮通风管．管长1.8米，管口直径1分米，如果每平方用油漆0.5千克，至少要用油漆多少千克？
<gadget id="calculator">0.562 * 100</gadget>
<output>56.2</output>

<result>56.2</result>