Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 26°C. We apply continuously 94°C heat to the field 3x6
What is the temperature (rounded to whole numbers) in the field 4x2 after 87 iterations according to the Gauss-Seidel iteration

Field in the beginning

26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626
26262626262626262626

Field after 4 iterations (rounded after 4th iteration)

4688999863
610131415151514105
813161920202017137
814202425252320158
917283936312723179
1024477557413225189
12327216982493526189
1127507859423124168
818304036292317126
491418171512963

Temperature in field 4x2 after 87 iterations: