20
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
bbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbb
cccccccccccccccccccc
cccccccccccccccccccc
dddddddddddddddddddd
dddddddddddddddddddd
eeeeeeeeeeeeeeeeeeee
eeeeeeeeeeeeeeeeeeee
ffffffffffffffffffff
ffffffffffffffffffff
gggggggggggggggggggg
gggggggggggggggggggg
hhhhhhhhhhhhhhhhhhhh
hhhhhhhhhhhhhhhhhhhh
iiiiiiiiiiiiiiiiiiii
iiiiiiiiiiiiiiiiiiii
jjjjjjjjjjjjjjjjjjjj
jjjjjjjjjjjjjjjjjjjj
kkkkkkkkkkkkkkkkkkkk
kkkkkkkkkkkkkkkkkkkk
llllllllllllllllllll
llllllllllllllllllll
mmmmmmmmmmmmmmmmmmmm
mmmmmmmmmmmmmmmmmmmm
nnnnnnnnnnnnnnnnnnnn
nnnnnnnnnnnnnnnnnnnn
oooooooooooooooooooo
oooooooooooooooooooo
pppppppppppppppppppp
pppppppppppppppppppp
qqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqq
rrrrrrrrrrrrrrrrrrrr
rrrrrrrrrrrrrrrrrrrr
ssssssssssssssssssss
ssssssssssssssssssss
tttttttttttttttttttt
tttttttttttttttttttt