= Solution
The displayed procedure calls `Find-Set` \b[$2|E|$ times explicitly], since it tests the two endpoints of every edge. Each successful `Union` decreases the number of sets by one, from $|V|$ initially to $k$ finally, so \b[there are $|V|-k$ `Union` calls].
These are calls at the displayed pseudocode level. If a concrete `Union(u,v)` implementation performs two further internal finds rather than accepting already found roots, its implementation adds $2(|V|-k)$ find invocations. Counting those separately avoids confusing the procedure's explicit call count with the implementation of a <disjoint-set union operation>.
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