定义在R上的奇函数f(x),当x≥0时,f(x)=log12(x+1),x∈0,1)1-|x-3|,x∈1,+∞),则函数F(x)=f(x)-a(0<a<1)的所有零点之和为( )
-- Are you going to Sam's birthday party the day after tomorrow?
-- I'm not sure. I will go with you if I _______.