d:0:`day07
r:({x@&&\~x=" "}'d)!{","\((">"\x)[1]^" ")}'d  / right hand sides
w:(!r)!{"i"$x@&(x>47)&x<58}'d                 / weights

*(!r)^,/. r                                   / fbgguv

W:{+/w[x],,/o'r@x}                            / recursive weight
w[j]-f-*c^f:W@j:r[i;**{1=#x}#.=c:W'r@i:b@*<W'b:&{$[#x;~1=#?W'x;0]}'r]   / 1864

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