((1/2)+(1/3)+(1/4)+...(1/15))+((2/3)+(2/4)+...+(2/15))+( (3/4)+(3/5)+...+(3/15))+...+((13/14)+(13/15))+(14/15).
((1/2)+(1/3)+(1/4)+…(1/15))+((2/3)+(2/4)+…+(2/15))+((3/4)+(3/5)+…+(3/15))+…+((13/14)+(13/15))+(14/15)．
<result>52.5</result>