Problem $26\mathrm{.}1-7($p$714)$

Suppose that, in addition to edge capacities, a flow network has vertex capacities. That is$,$ each

vertex $v$ has a limit $l(v)$ on how much flow can pass though $v.$ Show how to transform a flow

network $G=(V,E)$ with vertex capacities into an equivalent flow network $G^{\text{'}}=(V^{\text{'}},E^{\text{'}})$ without

vertex capacities, such that a maximum flow in $G^{\text{'}}$ has the same value as a maximum flow in G$.$

How many vertices and edges does $G^{\text{'}}$ have?