Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 19°C. We apply continuously 78°C heat to the field 5x7
What is the temperature (rounded to whole numbers) in the field 0x6 after 117 iterations according to the Gauss-Seidel iteration

Field in the beginning

19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919

Field after 4 iterations (rounded after 4th iteration)

3456666642
489111111111074
59121314141413105
611131516171615116
611141618202017137
611141825322822158
611152340614530189
6101628591386435199
48122239604226157
247111824201484

Temperature in field 0x6 after 117 iterations: