Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 21°C. We apply continuously 126°C heat to the field 5x8
What is the temperature (rounded to whole numbers) in the field 9x4 after 85 iterations according to the Gauss-Seidel iteration

Field in the beginning

21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121

Field after 4 iterations (rounded after 4th iteration)

3567777652
5810121212121184
610131516161614116
712151718181816126
712161819201917137
712161821252421158
712162131423727189
6111628548861372110
591634822078843219
25102143744625136

Temperature in field 9x4 after 85 iterations: