20
ddabbbcbaabcbddcbadcdcbdcccdcccdacbbcadacabbcbdbdcaabbcccaacdbbcddbadbddbdbcbcdbabdddddcbcbadacbbcbadddbaccbcaaaccdbdcdaaacddbcacbadbdacdbdaaacacdabdccbdddacadaabdcaccacccccdbbcbaadbacbcbadccacbdccdcddbcccbabcabdbacbcdadcaabbadaddacbdaccaacddbccccadabcdbdbbcbccabadbbbdccbabbbaaaaaddcdaadbbdcddcabddbaccdacaabdcaddcaaddbbdabcdbbbccaddbdbabaccababbcddccdcbbbcaadddcacaabdbaadccacccabcd
bbcdbbdacbdbbbbbdcadabaababbbdabdcccccabccdcbbadbbaacbabcbdbbddbcdddccbadcbccbdcdadbadacdbcdddddccadacbbcabadcbbbbacbccacdaacbccdbaccbdbacbddacdbaacdbddacdcaabdbbbddbcadcbbcabdcaaacaacddaaabbabdacdacdaddcccdbdbcabdddabbcdcdcbcdcbcdcdabbbddcddbbbbdbcdbcbdcbbbcdbbbbbadcddbbbdddccbdabddbadbdbdddcdabddacaaacdacacdbdbbbccacdaddadccdcbdaddcaaabacabbcaadababdbdccbddddddbadbbdaaccbbcaaaacadbabbbacddabdcdabaaaadcdcabbbca
accddbadcbdccccbbccaadaaaaabbbcbdcddaccdbdaacdcddcaaaacbcdcbaaadaaaaccbbbdbbadcddacacccadcdcbdcddcdadcacabaaadaacbbcbcaadadadabddbacaacdbadadaaacaddbdabbbaabbbcdacbdcbbaacbdbdbdbadaddbbbbbcaccaddccdaccbadcadabcaaabdaadbdaaacbdabcacaacaacacdddbbbabdbadbbcdddadbcddacaabbdddaadbccccbccaacdbadbbabdbcadbbcabdbabadbcacccbaddcdacbddadbabbccdadabcadddbcbdadbbaccbdbadddcabb
dbddcaabbabcabcdbccbacdcbcacadccbacccbcaacdaddcd
acacaadaababddcdaabbbddaddababadcdaabadadcbddccbaddbbdccbacbddcddccabdccaccabadcdaabdccabcadabcdaadcbacab
aadcacaabcbabdabcbddbabcdbacbdbdbcbbabaaaadbbdabdadbcacabccbbbdcbdacaadcaddaacdacdabacddacbabacdabaddcacbdddadcdabbddaacddbacbdadabbbdbcadbadbbabadacdcddbbcbbbdcababbaccbabdbaadddcaabdcbdacdcabccabdcbddbdaaaaabbcbacbcadbaabbbcbdacbcababbacacdbddaddcaabcabddadbbdacbbaabccbdcc
cbbcdbdbbbacabcadacccbabbdcaaaddbabbdbcddbaddacdacadaaabbbddcdacbcbcccdccddabbdcacaaaaaabbacadccbbdcbaaadbbdadbbdaabababdbcbacccbdadcdcbdbaaacadbadbdaabdaadacadbccaadccbadbbbcbbcbccdaabcacbbdaccdadacaadaccbcbaddccdbdccdbbcccdabdbcabcadccbbdbacdacdbbbdacadcaccadbadcdcabbaabdbaaabdbcbccdddddaacbddcbabacbbacacbbabaabaadccccdcadddaaddbbddaaccdbbcddbbbdccacaddcdcdbdcdcbaacdbcbdcdaccadacbbdbbdcbcbcbdbbbbbbdbcdbdcaabcdccbaddcbcabadcabcadcaaabdcddbadacbcabdccdaddaacaacabbcbdacaadcaadbdbdbdabd
abaadcabcccabbcabcbbbaacbbddcbddcdcdadddcaabdbbccbcbbcdbacdaaacbddbdadcdcabbabbcdbddbadabddbcdcdcaddacababdaaaacdcbaabbbddbcacdccdcbdcaddbbdcbcdaabacddbbbbccbadcbcbbaaacdbbaccacaccccdaacaddddccadccbdbddcbccddcbdcbbddcadddddccbcdcbabcdaabbbabaabdcaaadccdbcccdaaccbdaacacdaadbcabcbbdccbcbbdbdaccacccbbaadbacdbbccbddcdcabdcdbcabcccdcdddadabbbbcbbaabcbbdbacdcbdbdbdbabadccbacacddabbdbaabccadaabcddaddbcdadaacaaccbcdccacdddcbcaaadacdcbbcaadbdabdccbdcdaaccdaaccabdcacbdaabcaddcbbcddbacdacb
dbdbbcaadaadbbccabcbadacdabbcdbcbbcadbadaababbdbaccdabbaadbabbaacabcddbacabbcbcaddababadddbddacbbbaaaadcddaaacbdbcbbbccaacddccbcdccadadbcccbdccadacdabdbaddbcdcdadcadabdcddbddbbdcdddcbcbaadbcdddcbbdbbccdadcbcbdcacdcccdcdadadbababaadccabdacdbdddddbabddabbdcbbccdbcbdcabcbdddccaabdbdbbcbddbabbcddacdbdcbacaadcbbabcbbadbabcabdaddbdbbcdcbdbccccababdbddcddcaccbccbcdddacadddcaadccdaddddbbdbbdcccdbbcddacbabccacabcdbdadcacbcbdacdbdcaaddadbacdddccb
cbdaaacdabddcadbbccccaddbccbdbabbcdcbccbccdbaadddaacccaabaadcbaaabcdcdadcdddccdcdaaaacacccaadcccbdbdbcccadacbdacdcabcbcccaddccccbcadcadca
ccbcacabbbbdcaaacdaaaabcddddcbcdaaadbaaacccaacbccdaabacdbdbaacdccbcaacdbdabbcbddcdadbccabcacccbdbbbaaaaadbaacababacacccdbdcadabaadddddbdbdbddbdcaacdaaadbadbadabbaaccdaabdcacccddabbcdcbddadcaddadddabddaddbccccaadcdbbccccadaabbcabdacbdcdbcbacaacbaabcbabcacdcbcccabbaccccdbdcdbdbadcdaadbcddddbdaccbcdcbdcdacbbadacbcccacadabaccbaabdaadbabaddbaabbcabbcdcddabbddccb
dcbdcbcabdbbcbcdacdbddabbabcbdcabbbcaabdaccbcaacccdbcaadbacdadccdbcbaabdaabcadcaabacdcdbbaabcdaabbadcdcabdbaccc
abacaacdcdabbcdbbdbbcbdadbdcddbddaacdbadddacaddccddbbbddbaddcadbdcdcdddddccbdbcdbccaacdbdcabcabbbcbcabacbdbddcdbadcdbbaddcaacbdbbccbccacbadbdadbcdbdbbcacbcdbddbacccbddadbdcdccbadcbdcacaabaddcaddbcdbbaadcdbbcadcbddcaaadabcbabcabbdbdbadbcbadccaddcdbadacbbccadbbadacabbabcbcddbbaadbbdaccabcbcbacbcbdbaaaa
ccbadbacdddbababddccaacababaadcdabccbadcbddcaaddccdccbadbcddcbcccbdabdbcdcbaccdcbacaddcaabcabbcdbbaddddbcbdccdccbaccacbccdcccdadcaddddbcdababddbcbccdbadccccddbcdaaadacbbcacacbadaccbcbdacacacbadddbddadcdddaadaddca
dcbacadddcbdcdabbbbacdcabbbbcdadcabccaddbbbdcbcadcadabaadcbbacccccdccabdadbbcaacadddabdbbcadcbbdacaabcaddbdbcadadacdcbbabcbdacbdbddbcadabbdbddcbbaacdaddbabbddbbaacdabdadc
acabadbdaadbbbacdadccbbbacadabdcbbbdbacabddcbbaddaddaabcaadcaadccccbbdcbccbcdabcbbcdcdbccbdadbbdbbdabbcbabddcacabcdbcacdccaadbcadbadbddabbbadacdcbaababccdcbbcadbadaddbddabccdddcacadcbddbcaacddcacbacbdabbacdadaacdbcdaadddddbcccccdbbccabcaccaababdbbccdcbdbaadabdbaacbabcbcdaacddcdbcbcdcadbaabacadabacbbdcaddcabbbdadbbbdbdcbbbbdcaacaccbcabbdddcacdddaddabcaddcaacbbbdcdddadcdabbbbcbcaaacccbcbdccbbabdddbcddbcccacbbabbdaacaaacbcbdbdddacbabbdccccadbdbcabaaabbabbbbcbdcccdcadbbcd
cbacbcccbaddbcadddbabdcbbdaabddaacbdcbadaddcbbaadbdbdbbdbbbbbdacdddcddccbadaabdadbcdbdaaddacbdadccadbadddbaaaacdbccabbcbddcadddabdcdbadadcccaabdbdbbbcabbccbddbdbcdaaabdcddddacdbbdcdcbabaabbbdbcdbaccababaccdaacabbdccabddcbccccbaabaadbbdcbdabcacdcbdbcbcdcccbddcbdbcdbbdccacbdbaabcbbabacbcddadcacdacbcddbabaddcbddbbdacbabcccbdadcdcaddcdaaaacbbdccdcaacbbcadadbcadcbbcbabdcbadcaccabdacdcdcdabdddaadbcddddbdbdbaddbbacabbdacadbcbbdbbccbbbadacacbdaacddabaaddbcaddacbccaccddadcdabcaddcdbbbabadacbdcccd
acaacccdabaccbabaccbaaddcdcdbbbdccbcdcacccddbbddccbdbcccbdcbdddaccdacbadabacbbddcbddcbccdad
acbdcabdadcdaaabaadbcadddccdcbcacbbdaaacbdcddbadccdbdcbdaabbabdacbbbddcadadaaccdbacaababbbbaccdcbccaaadababbcacbbadaadbadbcadabcacbbbdabdbaabddacdcaddcadbdcabdbabaadbccbdaaacdababbadcabbdbbcbacbccaaaabaabcdaacddaddcaccddbbdcabbaadbdbdabdbdbbcdbccaacbacccdadac
adcacbcdadbbcbacaacccbaabaadbbcdaccbacccdbcbadbdacabbabaccacacaccdcadcdabcdbdadabcaaabbbbbddbbcddbabccaababaacbbbaccdbcadcabbbabdaabbdadadcaabaadabdabdbcacbaabddbadddbddbbddcbabdbdbddbbdacaddadcdbaddbcbdcacbbdddddcccaabbbdbddcbababbbbadabcdaddacadbccbadcabcdccdbccddadccacbccbaacdcbddaccbdbbdabaaccdddaacbbaccabcbadcdbcccbddcccbaddbcbaaabab