Calculation: 8-9+10-11+26-41+42=how much.
计算：8-9+10-11+26-41+42=多少．
<gadget id="calculator">8 - 9</gadget>
<output>-1</output>

<gadget id="calculator">10 - 11</gadget>
<output>-1</output>

<gadget id="calculator">26 - 41</gadget>
<output>-15</output>

<gadget id="calculator">(-1) + (-1) + (-15) + 42</gadget>
<output>25</output>

<result>25</result>