2 it's very similar to math concept of range, it's actually very useful to find particular numbers among a range of numbers,
but you have to figure out how to find that number. For odd number, I initially used minus one, then figure out that it should be plus one on the basis of even numbers identified among the range.
It's not about range but I wonder if we could provide a list of numbers and identify numbers that meet requirement among them.
grace-xing6
gxing