给定一个矩形，把这个矩形拆分成若干个正方形，这些正方形的边长相同，问怎样拆分，正方形的边长是最大的，并把这个边长输出来。-given a rectangular, the rectangular split into a number of square, the square-the same side, asking how separation of the square is the largest side length, and the side length output.