Find one pair of elements $x,$ $y$ in $U(8)$ such that $\langle x \rangle$ and $\langle y \rangle$ are proper subgroups of $U(8)$ and that $\langle x,y \rangle = U(8)$. Be sure that $x<y$ with $1 \leq x, y<n$.

$(x,y) = ($ $,$ $)$