When Ma Xiaohu was doing an integer subtraction problem, he regarded the 1 in the unit digit of the subtrahend as 7, and the 7 in the tens digit as 1, and the difference was 111. What is the correct answer?
马小虎在做一道整数减法题时，把减数个位上的1看成7，把十位上的7看成1，得出差为111，则正确答案是多少？
<gadget id="calculator">111 + 17</gadget>
<output>128</output>

<gadget id="calculator">128 - 71</gadget>
<output>57</output>

<result>57</result>