ένα καφέ παρακαλώ

There's this crazy idea going round that, if Greece does in fact leave the euro, all Greek euro notes will become invalid.  Crazy because there is no such thing as a Greek euro note - a euro is a euro is a euro.  Notes are printed in countries throughout the eurozone, so there will indeed be notes that were produced and printed in Greece (you can tell them because the serial number will begin with the letter Y) but this doesn't make them "Greek" and fear not, they will continue to be worth their face value irrespective of whether Greece remains in the eurozone or not.