The streets of a city are represented on a map as straight lines that divide a square into 25 smaller squares of side 1. (The borderline of the city is considered to be the union of 4 streets.) There is a snow plow at the bottom right corner of the bottom left square. Find the length of the shortest path for the plow to pass through all streets and come back to its starting point.

Let's think step by step and output the final answer within \boxed{}.
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