There are several problems.

The ',2' arguments you're trying to pass to Serial.print need to be inside the brackets, as PaulS pointed out.

In your case the numbers you're printing are integers (whole numbers) so for example 5/2 is equal to 2.5 but when you use integer arithmetic the '.5' is lost and the answer is 2. If you're printing integers then the second argument isn't required anyway.

In your print statements you are printing values like this:

```
Serial.print(RES = RES/2);
```

That has two effects: it prints the value of RES/2, and it also assigned that value back to RES so RES is no longer equal to five - this would affect the results of all the subsequent calculations. If you only want to print the value of RES/2 without changing the value of RES in the process, then you can do it like this:

```
Serial.print(RES/2);
```