= Solution
For input $|0\rangle_S$, the <controlled-NOT gate> fixes $|00\rangle_{SC}$, which is the ideal two-copy <pure state>. Thus its <global cloning fidelity> is $F_0=1$. For input $|+\rangle_S$, the actual output is the <Bell state> $|\phi_+\rangle$, whereas the desired output is $|++\rangle$. Their overlap is
$$
\langle++|\phi_+\rangle=\frac1{\sqrt2},\qquad F_+=\frac12.
$$
With the given equal input <probabilities>,
$$
\boxed{F_0=1,\qquad F_+=\frac12,\qquad
\overline F=\frac12\left(1+\frac12\right)=\frac34.}
$$
These values use the specified <squared quantum fidelity> for the full output, rather than a one-copy marginal fidelity.
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