bamboo pole is 8.6 meters long. After being inserted vertically into the river, the length of the part inserted into the mud is 1.2 meters, and the depth of the river is 2.8 meters. How many meters is the length of the part exposed to the river?
一根竹杆长8.6米，竖直插入河里后，插入淤泥里的部分长1.2米，河水深2.8米，露出河面的部分长多少米？
<gadget id="calculator">8.6 - 1.2 - 2.8</gadget>
<output>4.6</output>

<result>4.6</result>