An weak type sobolev multiplication theorem

Question

Suppose that $f_i\rightharpoonup f$ in $W^{1,p}$ and $g_i\rightharpoonup g$ in $W^{1,q}$ with $q=\frac{np}{n-p}$, what the best $r$, for which we have $f_ig_i\rightharpoonup fg$ in $L^r$ (maybe $W^{1,r}$)?