Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 18°C. We apply continuously 167°C heat to the field 9x7
What is the temperature (rounded to whole numbers) in the field 4x2 after 139 iterations according to the Gauss-Seidel iteration

Field in the beginning

18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818
18181818181818181818

Field after 4 iterations (rounded after 4th iteration)

3456666542
47910101110974
5911131314131295
610131415151514106
6101315161616151411
6111415161717192627
6101315161719305376
5912141516214192228
47910111217305577
2455679152325

Temperature in field 4x2 after 139 iterations: