Let $ABC$ be a triangle with orthocenter $H$ and $\ell$ a line that passes through $H$, and is parallel to $BC$. Let $m$ and $n$ be the reflections of $\ell$ on the sides of $AB$ and $AC$, respectively, $m$ and $n$ are intersect at $P$. If $HP$ and $BC$ intersect at $Q$, prove that the parallel to $AH$ through $Q$ and $AP$ intersect at the circumcenter of the triangle $ABC$.