I have a problem in a cryptography exercise that i can't solve and it is killing me :( It is like this:

We have a text encrypted by a Enigma I machine with 3 rotors (selected from a set of 5). The plain text is only a repetition of the letter "Z", and the encrypted text is here: http://pastebin.com/1aBuRSpi

The goal is to obtain the key (the configuration of the enigma machine: initial position, rotors used...) used in this case.
Can someone help me?