Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 28°C. We apply continuously 68°C heat to the field 7x4
What is the temperature (rounded to whole numbers) in the field 4x0 after 67 iterations according to the Gauss-Seidel iteration

Field in the beginning

28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828
28282828282828282828

Field after 4 iterations (rounded after 4th iteration)

47899109974
711141516171717147
8141820212327312412
9152022253143594019
91621242838631295925
10172124283650654421
9162124273138413116
8151921232629282211
611141617192018147
367891010973

Temperature in field 4x0 after 67 iterations: