块 1:<br />
1 2 3 <br />
4 5 6 <br />
7 8 9 <br />
10 11 12 <br />
<br />
块 2:<br />
13 14 15 <br />
16 17 18 <br />
19 20 21 <br />
22 23 24 <br />
<br />