I'm working on a Regex with php, but I have a problem :

I would like to make a condition : If you meet the "-" character, the next character must be an UPPERCASE character.

I did researches and found that we can use the condition like this : (?(?=regex)then|else)

Unfortunately, it's not working.

**Here is my Regex for the moment :**

```
[A-Z][a-z]+[A-Za-z-]*(?(?=[-])[A-Z])

```

The string have to respect the following conditions :

* First letter as UPPERCASE
* Second letter and others as LOWERCASES
* The only special character "-" is accepted
* If met, the "-" have to be follow by an UPPERCASE

Currently, with my regex, the following result is matching (but should not) : Pilar-ackerman

The string that should match would be : Pilar-Ackermam

Could someone help me plz ?

**UPDATES FROM COMMENTS**:

A string like `PilAr` is matching, and should not :(

I don't need to allow multiple "-" symbols in the input string.