csharp, 324 bytes

Result

AC

Duration

847ms

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();foreach(int z in Enumerable.Range(0,9))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

65 14 65
17 35 32
31 04 55
27 30 99

stdout

11898

stderr

strace