There are two numbers: 515, 53. Subtract 11 from the first number and add 11 to the second number. This counts as one operation. After how many operations, the first number and the second number are equal.
有两个数：515，53，将第一个数减去11，第二个数加了11，这算一次操作，那么操作多少次后，第一个数和第二个数相等．
<gadget id="calculator">515 - 53</gadget>
<output>462</output>

<gadget id="calculator">11 + 11</gadget>
<output>22</output>

<gadget id="calculator">462 / 22</gadget>
<output>21</output>

<result>21</result>