Find the value of the letter formula: given a=308, b=854, c=292, find the result of a+b+c.
求字母算式的值：已知a=308，b=854，c=292，求a+b+c的结果．
<gadget id="calculator">308 + 854 + 292</gadget>
<output>1_454</output>

<result>1_454</result>