Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 7°C. We apply continuously 67°C heat to the field 9x8
What is the temperature (rounded to whole numbers) in the field 4x2 after 77 iterations according to the Gauss-Seidel iteration

Field in the beginning

7777777777
7777777777
7777777777
7777777777
7777777777
7777777777
7777777777
7777777777
7777777777
7777777777

Field after 4 iterations (rounded after 4th iteration)

1222222221
2334444431
2345555542
2456666542
2456666643
2456676654
245666671011
2455667112130
2344457153590
112223491827

Temperature in field 4x2 after 77 iterations: