212121XX21211X12
212121XX21211212
2121212222211X12
2121212222211212
X11X11XX11111X21
X11X11XX111X1X21
211221XX11111X21
211221XX111X1X21
11X12111X1211211
11X12111X1212211
21X12X21X1211211
21X12X21X1212211
