Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 40°C. We apply continuously 70°C heat to the field 3x5
What is the temperature (rounded to whole numbers) in the field 4x0 after 84 iterations according to the Gauss-Seidel iteration

Field in the beginning

40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040
40404040404040404040

Field after 4 iterations (rounded after 4th iteration)

6912131314131295
916202224242321168
12202631323231272011
13243544434037322312
14305073604942352613
163670144805645372714
16335477645244362613
14273949474338322211
1019263132302823168
5913151616141284

Temperature in field 4x0 after 84 iterations: