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Description The map of Berland is a rectangle of the size n × m, which consists of cells of size 1 × 1. Each cell is either land or water. The map is 阅读全文
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Description Modern text editors usually show some information regarding the document being edited. For example, the number of words, the number of pag 阅读全文
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Description There are three friend living on the straight line Ox in Lineland. The first friend lives at the point x1, the second friend lives at the 阅读全文