Three objects younger modern app-driven people probably don't know.
1. 1€ coin (~75 rubles) you can use in most countries of EU🇪🇺 if you're not paying everything by card.
2. 10 French Franc coin (~115 rubles) valid before 2002 in France🇫🇷 if you're old enough to remember.
3. 1 coin (45 rubles) for the St.Petersburg🇷🇺 Subway if you weren't using Uber the whole time.
What do these objects have in common? Their diameter. I can use all three of them to get a trolley in a supermarket here in Germany🇩🇪. 🤓
Well, then you need to know, that there is 2 rub coin same diameter:D