12 3
c
abcdefghi...
labcdefghij.
klabcdefghij
jklabcdefghi
.jklabcdefgh
...klabcdefg
k....labcdef
jkl....abcde
ijkl........
hijk........
ghij........
fghi........
r
aabbccdde...
bbccddeeffg.
ccddeeffgghh
ddeeffgghhii
.effgghhiijj
...ghhiijjkk
i....ijjkkll
jjk....kllaa
kkll........
llaa........
aabb........
bbcc........
a
kllaabbcc...
ijjkkllaabb.
ghhiijjkklla
effgghhiijjk
.ddeeffgghhi
...ccddeeffg
a....bbccdde
kll....aabbc
ijjk........
ghhi........
effg........
cdde........