X X1(1,n) X(2, n X1(3, no)W4 Wi x(o                0 0 0 0 1 0 4 4 4 4 0 0 1 2 3 1 0 4 4 4 4 0 0 2 0 2 1 0 4 4 4 4 0 0 3 2 1 1 0 4 4 4 4 0 0, 0, 1, 1, 2, 2, 3, 3, X n W W W W x n X n W W W W x n X n W W W W x n X n W W W W x n                                        0 0 0 0 0, 1 1 1 1 1, 1 1 2, 1 1 1 1 3, 1 1 x n j j x n x n j j x n                           