P3101 [USACO14JAN] Ski Course Rating G

The cross-country skiing course at the winter Moolympics is described by an M x N grid of elevations (1

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The ski course is described by a 3 x 5 grid of elevations. The upper-left and lower-right cells are designated as starting points. From each starting point, we must be able to reach at least 10 cells. The difficulty rating of the upper-left starting point is 4, and for the lower-right it is 20.