You've just moved into a perfectly straight street with exactly n identical houses on either side of the road. Naturally, you would like to find out the house number of the people on the other side of the street. The street looks something like this:

1|   |6
3|   |4
5|   |2

Evens increase on the right; odds decrease on the left. House numbers start at 1 and increase without gaps. When n = 3, 1 is opposite 6, 3 opposite 4, and 5 opposite 2.

Given your house number address and length of street n, give the house number on the opposite side of the street.

Examples

over_the_road(address, n)

over_the_road(1, 3) = 6
over_the_road(3, 3) = 4

Tests

over_the_road(3, 5)
over_the_road(7, 11)

Good luck!

This challenge comes from rge123 on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

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