1/3+1/6+1/12+1/24+1/48+1/96
=1/3+1/2-1/3+1/3-1/4+1/4*1/2-1/6*1/2+1/6*1/2-1/8*1/2+1/8*1/4-1/12*1/4
=5/6+7/96
=87/96