Given a positive integer $n$, we want to represent $n$ as a sum of as many positive integer terms as possible, where each number can be used at most once and no two consecutive numbers can be used.
Input
The first and only line of input contains an integer $n$ ($1 \le n \le 10^{18}$).
Output
Your program should output a single integer: the maximum number of terms in the requested partition.
Examples
Input 1
6
Output 1
2