You are getting b = 8 on sololearn compiler, on some other compiler you may get b = 0 or any other random value.
The rule is that any variable must be initialized before it's first use, till then it contains garbage value
in int b = b; the variable b is not initialized before first use.
Because you are trying to assign an empty value to b. If you do this:
It will be ok, just because i have assigned the same value of b to c (5 in this case). In your exercise this don't happen. So, try to assign an int value and then retry.