Iahub got lost in a very big desert. The desert can be represented as a n × n square matrix, where each cell is a zone of the desert. The cell (i, j) represents the cell at row i and column j (1 ≤ i,
格言:我们的命运由我们的行动决定,而绝非完全由我们的出身决定。 享有特权而无力量的人是废物,受过教育而无影响的人是一堆一文不值的垃圾。 (Men of privilege without power are waste-material.Men of enlightenment without influence ate the poorest kind of rubbish.) July 20