KöMaL 2013 C1150
A square made up of an odd number of small squares is drawn on squared paper. We want to draw a closed polygon along grid lines such that it passes through every lattice point in the interior or on the boundary of the large square exactly once, and it does not leave the large square. Express the length of the polygon in terms of the length of the side of the large square.
Official text KöMaL. Quoted with source.
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