Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 21°C. We apply continuously 156°C heat to the field 0x5
What is the temperature (rounded to whole numbers) in the field 2x6 after 68 iterations according to the Gauss-Seidel iteration

Field in the beginning

21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121
21212121212121212121

Field after 4 iterations (rounded after 4th iteration)

3567777652
6911121213121184
1116171717161614116
2730262320191816126
7357402924222017137
21595523426232118137
7662443226232118137
3135312622201816116
141920181615141284
6999887642

Temperature in field 2x6 after 68 iterations: