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 157°C heat to the field 9x7
What is the temperature (rounded to whole numbers) in the field 2x2 after 72 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
2456666543
2456666677
245667691822
2456669204469
245566123181211
23444510234870
1122236122023

Temperature in field 2x2 after 72 iterations: