\(OABCD\) is a pentagon in which the sides \(OA\) and \(CB\) are parallel and the sides \(OD\) and \(AB\) are parallel. Also, it is given that
\[
\frac{OA}{CB}=2,\qquad \frac{OD}{AB}=\frac{1}{3}.
\]
If \(\overrightarrow{OA}=\vec{a}\), \(\overrightarrow{OD}=\vec{d}\), then
\[
\overrightarrow{AD}+\overrightarrow{OC}+\overrightarrow{DC}=
\]