$(i=p=v=FS=_)=$0{for(;(i+=3)<=NF;p=j<10&&j-7||$(i-1)~"\xb8"?j:(v+=(p?p:1)*(j>7?j%2*90+10:1e3))*0)j=index("\x80\x8c\x89\x9b\x94\xad\x83\xab\x9d\x81\xbe",$i)}$0=v+p
Note that non-ascii characters in the above source code will be escaped (such as \x9f).