For any real number y, let [y] be the greatest integer less than or equal to y and let {y}=y−[y]. For n=1,2,…, and for x∈R, let
f2n(x)={[xsinx],x=0, 1,x=0,andf2n−1(x)={{xsinx},x=0, 1,x=0.
Then limx→0∑k=1100fk(x) equals __________
Numerical answer: type the number (no options).