csharp, 291 bytes

Result

WA

Duration

735ms

Code [DL]

using System;using System.Linq;class A{static void Main(){char[]c={' ','\n'};int[]a=s.Split(Console.In.ReadToEnd()).Take(12).Select(Int32.Parse).ToArray();for(int z=9;z-->0;)a[z]-=a[9+z%3];Console.Write((a[7]*(a[0]*a[5]-a[3]*a[2])+a[6]*(a[4]*a[2]-a[1]*a[5])+a[8]*(a[3]*a[1]-a[0]*a[4]))/6);}}

stdin

42 06 32
25 55 58
51 91 30
05 08 48

stdout

Compilation failed: 1 error(s), 0 warnings

stderr

/tmp/code.cs(1,85): error CS0103: The name `s' does not exist in the current context
Cannot open assembly '/tmp/code.exe': No such file or directory.
rm: can't remove '/tmp/code.exe': No such file or directory

strace