Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 8°C. We apply continuously 78°C heat to the field 7x4
What is the temperature (rounded to whole numbers) in the field 3x4 after 50 iterations according to the Gauss-Seidel iteration

Field in the beginning

8888888888
8888888888
8888888888
8888888888
8888888888
8888888888
8888888888
8888888888
8888888888
8888888888

Field after 4 iterations (rounded after 4th iteration)

1223333321
2344556763
2456681319158
346681430503215
35671021511285321
3567101835553617
356791421272111
24567101315127
2345578874
1222334432

Temperature in field 3x4 after 50 iterations: