Calculation: ((13(1/11)+11(1/13))/((4/11)+(4/13)))+((13(1/13)+12(1/12)- 11(1/11))/(13(1/13)-10(1/11)+11(1/12))).
计算：((13(1/11)+11(1/13))/((4/11)+(4/13)))+((13(1/13)+12(1/12)-11(1/11))/(13(1/13)-10(1/11)+11(1/12)))．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>