Surely their price is considerably low, but given the limited locations where people can actually get access to the water, it is not that cheap. Imagine waiting in line with your mobile phone and your cup to get a little sap. You would want a huge water tank to cut down the frequency of fetching water. Good for motorhome users though.

Definition of natural numbers is the same as non-negative numbers, so of course 0 is a natural number.

Don’t know what can 20k euro achieve. Russia must be lacking of money.

That’s so sad, i cannot imagine myself growing old in such a corrupted country.