h
:1
s/[1-9]/&-/g
y/123456789/012345678/
s/-0/9-/
t1
s/$/--/
s/------/=/g
s/---/+/
s/.$/ & 1/
:
s/0=\{10\}/=0/
t
s/0==*/&987654321!/
s/0=.\{8\}\(.\).*!/\1/
t
H
g
s/\n0*/ = 6 * /
Note that non-ascii characters in the above source code will be escaped (such as \x9f).