Non-consecutive Summands

You are given a positive integer $n$. You want to write it as a sum of positive integers while obeying both of these rules:

• No integer may be used more than once (each integer appears at most once).
• No two consecutive integers may be used together (for example, $3$ and $4$ cannot both appear).

Subject to these rules, make the number of summands as large as possible. Find that maximum number of summands.

The first and only line contains an integer $n$ ($1 \le n \le 10^{18}$).

Print a single integer: the maximum number of summands in such a decomposition.