20
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baccababbc
bcccbaacbc
ccccacbaca
aaaaccabbb
cbbbacbaaa
aaabbaabcb
aacccbbacb
bcbccbcacc
caabacbcba
bcbcbbcbbc
cacccabcaa
abbababacb
aacaabbccb
abbcacaccb
caaccaacca
bcbacacaac
baccbcccbc
abbcaccabb
acbacccccb