It's way too slow.
LSPRR4TK5XL7FSO32Y54BWQOHJLAFJYEFWBE5TIXA2PMC42SRWFAC
WTUBAA5QTHPVRQYEX2QPFFA6XO3BFD4O7JDCR5LXMJVPIR5EI3LAC
TPSCSZKXKQAMSLMRACXSHWQ4OY7HPSJSJ4KTJY6HLHZQAJ5MDRZAC
7YBYT2LQML2PKEO6UO4444AGSASS664UCDXW2YO3ALB7THQHCEBQC
return undef; # FIXME