The sum of the two numbers of A and B is 3058. If the decimal point of the number B is moved one place to the right, it is equal to the number A. What is the number A?
甲乙两数和是3058．乙数的小数点向右移动一位就等于甲数，甲数是多少．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">3_058 / 11</gadget>
<output>278</output>

<gadget id="calculator">278 * 10</gadget>
<output>2_780</output>

<result>2_780</result>