csharp, 330 bytes

Result

WA

Duration

761ms

Code [DL]

using System;
class A{
static void Main(){
String s;
for(int i=4;i>0;i--){
  s+=Console.ReadLine() + " ";
}
int[] a=s.Split(' ').Take(12).Select(Int32.Parse).ToArray();
foreach(int z in Enumerable.Range(0,8)){a[z]-=a[9+z%3];}
Console.Write(-(a[7]*(a[3]*a[2]-a[0]*a[5])+a[6]*(a[1]*a[5]-a[4]*a[2])+a[8]*(a[0]*a[4]-a[3]*a[1]))/6);
}}

stdin

85 96 28
02 25 39
46 17 83
51 86 35

stdout

Compilation failed: 2 error(s), 0 warnings

stderr

/tmp/code.cs(8,22): error CS1061: Type `string[]' does not contain a definition for `Take' and no extension method `Take' of type `string[]' could be found. Are you missing `System.Linq' using directive?
/usr/lib/mono/4.5/mscorlib.dll (Location of the symbol related to previous error)
/tmp/code.cs(9,18): error CS0103: The name `Enumerable' 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