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Question $1$

Let $x$ be the length of a shortest path from $h$ to $f.$

Modify the graph by adding $2$ to all weights. For example, the weight of the edge $(h,$ a$)$ will be $2+2=4,$ etc.

Let $y$ be the length of a shortest path from $h$ to $f$ in the modified graph.

Find the product of $x$ and $y,$ that is $x^{2}y.$