There are $$10$$ members in a delegation. No two of them have the same height. Let $$N$$ be the number of ways in which they can stand in a line for a photograph such that

1) the leftmost person is the shortest,

2) the rightmost person is the tallest, and

3) in the line between the shortest and tallest person, there is exactly one person who is shorter than both of his immediate neighbours.

If $$N$$ can be written as $$100a+b$$ where $$a$$ and $$b$$ are positive integers less than $$100$$, find $$a+b$$.