python dictionary remove duplicates with error of +-1

Question

maybe someone can help me with this. I have a dictionary here:

print("levels: \n", SPYlvl)

{445: 8, 444: 6,
427: 6, 428: 4 }

I want to remove keys with numbers which is near +-1 in example: we have 428 which is repeated 4 times and we have 427 which is repeated 6 times

I would like to remove the 428 because it is +-1 of 427 and is repeated less.

the same with 445 an 444, I want only to leave 445 which is repeated more times.