f(x)=f(1/2-(1/2-x))=f(1/2+(1/2-x))=f(1-x)=-f(x-1)
so f(x-1)=-f(x-2)
so f(x)=f(x-2) f(x)+f(x-1)=0
f(1)=-f(0)=f(0)=0
so answer=0