The power plant brought in 972 tons of coal, out of the original 77 tons, 301 tons were used on the first day, 321 tons on the second day, and 350 tons on the third day. How many tons of coal are left in the power plant?
发电厂运来972吨煤，原来有77吨，第一天用去301吨，第二天用去321吨，第三天用去350吨，发电厂还剩多少吨煤？
<gadget id="calculator">972 + 77</gadget>
<output>1_049</output>

<gadget id="calculator">301 + 321 + 350</gadget>
<output>972</output>

<gadget id="calculator">1_049 - 972</gadget>
<output>77</output>

<result>77</result>