The key wheels were constructed so that the number of possible wheel settings were no less than 893 622 318 929 520 960. The transposition connection could also be varied in 8 basic patterns with 2 612 736 000 variations each. Therefore, the Germans and everybody else believed that the code was impossible to break, until Beurling came along and cracked the code by only using pen and paper, and, of course, his powerful mind! Like many other geniuses, Beurling was quite a special person. For instance, the Swedish Defence Staff was a little annoyed that he refused to work overtime, but insisted on only being available during normal office hours. In the beginning, nobody but Beurling could decipher the German messages, but soon copies of the G-machine were built. In the end there were as much as 20 copies of the G-machine that were managed by 170 people, both day and night. Beurling not only managed to crack the German code, but also the Soviet one, as well as the code systems of a number of unspecified countries at war and a few other neighbouring nations. This, in turn, enabled the Swedish Defence Forces and government to know exactly what was going on in Berlin, Moscow and London.