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 138°C heat to the field 2x4
What is the temperature (rounded to whole numbers) in the field 8x3 after 135 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)

6912131414131295
918252727262421168
15335048413632282111
256210680584639332412
36100245120735343352613
317211690665244362614
23486764554842352613
17324345434036312211
1121273030292722168
61013151515141184

Temperature in field 8x3 after 135 iterations: