When Huihui was doing the problem, because she was not serious, she copied the 3 in the tens digit into 8, and the 7 in the ones digit into 2, and the result was 3345. What is the correct result?
慧慧在做题时，由于不认真，把减数十位上的3抄成了8，把个位上的7抄成了2，所得的结果是3345．正确的结果是多少？
<gadget id="calculator">50 - 5</gadget>
<output>45</output>

<gadget id="calculator">3_345 + 45</gadget>
<output>3_390</output>

<result>3_390</result>