Three Strings Problem (Easy Version)

Let $P$, $Q$, and $R$ be binary strings of equal length $L$. **Define** $F(P,Q,R)$ as the minimum total cost to transform $Q$ into $R$ using the following rules: - You may flip $P_i$ or $Q_i$ for any index $i$ $(1 \le i \le L)$. Each flip changes $0 \leftrightarrow 1$ and costs $1$. - After all flips are completed, you may perform any number of **valid swaps** in the resulting string $Q$ at