php, 228 bytes

Result

WA

Duration

467ms

Code [DL]

<?php [$a,$b,$c,$d,$e,$f,$g,$h,$i,$j,$k,$l]=explode("",readline()." ".readline()." ".readline()." ".readline());$g-=$a;$h-=$b;$i-=$c;$j-=$a;$k-=$b;$l-=$c;echo(($e-$b)*($i*$j-$g*$l)+($f-$c)*($g*$k-$h*$j)+($d-$a)*($h*$l-$i*$k))/6;

stdin

05 96 39
10 97 84
05 56 46
71 96 45

stdout

0

stderr

PHP Warning:  explode(): Empty delimiter in /volume/CODE on line 1

strace