golfscript, 82 bytes

Result

AC

Duration

557ms

Code [DL]

"
"/);{' '/}%(\{[1$\]zip{{~}%{-}*}%}%.{}/{(+\(+(+[@]zip{{*}*}%{+}*}:q~\{}/\q- 6/\;

stdin

78 20 17
20 13 68
53 37 92
05 41 90

stdout

13573

stderr

strace