传说中，南极有一片广阔的冰原，在冰原下藏有史前文明的遗址。整个冰原被横竖划分成了很多个大小相等的方格。在这个冰原上有N个大小不等的矩形冰山，

这些巨大的冰山有着和南极一样古老的历史，每个矩形冰山至少占据一个方格，且其必定完整地占据方格。冰山和冰山之间不会重叠，也不会有边或点相连。

ACM探 险队在经过多年准备之后决定在这个冰原上寻找遗址。根据他们掌握的资料，在这个冰原上一个大小为一格的深洞中，藏有一个由史前人类制作的开关。

而唯一可以 打开这个开关的是一个占据接近一格的可移动的小冰块。显然，在南极是不可能有这样小的独立冰块的，所以这块冰块也一定是史前文明的产物。

他们在想办法把这 个冰块推到洞里去，这样就可以打开一条通往冰原底部的通道，发掘史前文明的秘密。冰块的起始位置与深洞的位置均不和任何冰山相邻。

这个冰原上的冰面和冰山都是完全光滑的，轻轻的推动冰块就可以使这个冰块向前滑行，直到撞到一座冰山就在它的边上停下来。冰块可以穿过冰面上所有没有冰山的区域，

也可以从两座冰山之间穿过。冰块只能沿网格方向推动。-According to legend, there is a vast Antarctic ice sheet, the ice sheet under the possession of the site of prehistoric civilization. If they had the entire ice sheet is divided into many equal-sized squares. N in the ice on the tip of a rectangle of varying sizes,

These huge Antarctic icebergs has and as old as the history of the tip of each of at least occupy a rectangular box, and will fully occupy the square. Do not overlap between the tip of the iceberg and there will not be connected to edge or point.

ACM expedition after the decision, after years of preparation in the ice to find sites. According to their information available in the ice sheet the size of a cell of a deep hole, possession of a prehistoric people made the switch.

The only you can open an account for this switch can be moved close to a grid of small ice cubes. Clearly, in the Antarctic is not possible to have such a small independent ice, so this ice must also be a product of prehistoric civilization.

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