f(36)=f(4*9)=f(4)+f(9),
f(4)=f(2*2)=f(2)+f(2)=p+p=2p不等于f(2)*f(2)(即p²)
f(9)=f(3*3)=f(3)+f(3)=q+q=2q不等于f(3)*f(3)(即q²)