csharp, 304 bytes

Result

WA

Duration

795ms

Code [DL]

using System;using System.Linq;class A{static void Main(){char[]c={' ','\n'};string s=Console.In.ReadToEnd();int[]a=s.Split(c).Take(12).Select(Int32.Parse).ToArray();for(int i=8;i-->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

08 86 65
01 43 39
03 96 55
66 14 15

stdout

Compilation failed: 4 error(s), 0 warnings

stderr

/tmp/code.cs(1,197): error CS0103: The name `z' does not exist in the current context
/tmp/code.cs(1,189): error CS0103: The name `z' does not exist in the current context
/tmp/code.cs(1,188): error CS0584: Internal compiler error: Object reference not set to an instance of an object
/tmp/code.cs(1,188): error CS0201: Only assignment, call, increment, decrement, await, and new object expressions can be used as a statement
Cannot open assembly '/tmp/code.exe': No such file or directory.
rm: can't remove '/tmp/code.exe': No such file or directory

strace