Running out of gas…

This happened to me and a friend three years ago. We wanted to go to the first concert of Michael Bublé in Austria. Since he was playing in Salzburg, we had to go and stay there. However, it was impossible to find a room in Salzburg, so we decided to stay in Linz, about an hour from Salzburg. We checked in, went up to our room, strolled through Linz and then got ready to go to Salzburg. On the way I realized that I had forgotten my wallet in Linz. My friend said: “Don’t worry, I have mine with me.” Before we arrived in Salzburg we were running low on gas, but since we were already a bit late we decided to go to the gas station afterwards. In the concert break we wanted to get some drinks, went to the bar and my friend wanted to pay for the drinks. Uuuuuuuuuuups, she couldn’t find her wallet either…Not only couldn’t we pay for the drinks, how were we supposed to pay for the parking ticket? And how would we get back to Linz without gas?