x1	x2	x3	x4	x5	x6	x7
1	1	1	1	1	1	1
1	1	2	1	2	2	2
1	2	1	2	1	2	2
1	2	2	2	2	1	1
2	1	1	2	2	1	2
2	1	2	2	1	2	1
2	2	1	1	2	2	1
2	2	2	1	1	1	2