A bamboo pole is 3.5 meters long. When the bamboo pole is inserted into the river, the part of the bamboo pole in the mud is 0.6 meters, and the part above the water is 0.7 meters. How deep is the river in meters?
一根竹竿长3.5米，将竹竿插入河中，竹竿入泥部分是0.6米，露出水面的部分是0.7米．河水深多少米？
<gadget id="calculator">3.5 - 0.6 - 0.7</gadget>
<output>2.2</output>

<result>2.2</result>