Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 17°C. We apply continuously 85°C heat to the field 3x6
What is the temperature (rounded to whole numbers) in the field 8x8 after 121 iterations according to the Gauss-Seidel iteration

Field in the beginning

17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717
17171717171717171717

Field after 4 iterations (rounded after 4th iteration)

2455666542
4789101010973
5811121313131194
59131717171513105
612213027231915116
718386245312317126
9256114768392618126
821416648332317115
61424322822171284
37111413119642

Temperature in field 8x8 after 121 iterations: