no idea, just had to go to MAD from SFO, UA put this up on its web-site and I said, no F--ing way. Got the same Fare on UA to FRA, then on to MAD on LH. (that said I have SWU as a 1K). If I were you, and wanted a pleasent trip, I would look arround, and gladly pay more for some other airline, I bet UA/LH will match the fare, as will others....
just my 2 sents worth.