On a planar field, you travelled $3$ units East from a point $O$. Next you travelled $4$ units South to arrive at point $P$. Then you travelled from $P$ in the North-East direction such that you arrive at a point that is $6$ units East of point $O$. Next, you travelled in the North-West direction, so that you arrive at point $Q$ that is $8$ units North of point $P$.
The distance of point $Q$ to point $O$, in the same units, should be ______________