Hello Valentin,
in addition to Keith's hint: Could it be that you won a product from these firms like Amazon? If yes, this is not a serial number, only a code with which you can request a serial number from Adobe. Please have a look at http://helpx.adobe.com/x-productkb/global/find-serial-number.html. (Start here: "When you purchased your product, you could have received ..." >>> How did you purchase your product?)
The following part, so I just see at least, ceased to exist on my Adobe website, everything takes place in the link from above. I leave it as an info yet, it might still fit for you. For this purpose, please click your way through to your Adobe Store and find the button "Get Serial Number". Fill in the form and after a while you will get the real serial number.
If necessary and for further questions click through http://helpx.adobe.com/contact.html or http://helpx.adobe.com/de/contact.html and if "open" please use the chat, I for may part had the best experiences. I quote from Adobe's employee Preran: The chat button is activated as soon as there is an agent available to help.
Hans-Günter