open String let rec($)s l=let(@),h=sub(s^s),length s-1in h<0&l.[2]<'3'&(l.[4]='1'||l.[4]='2'&l.[5]<'4')&l.[6]<'6'&l.[8]<'6'&()=print_endline l;for i=h/8*2to h do(0@i)^i+1@h-i$l^i@1done;;"123456789"$"0"
Note that non-ascii characters in the above source code will be escaped (such as \x9f).