Problems

# The Segments

Cut a segment with length L on the most quantity of parts the lengths of which are natural numbers, that from them it is not impossible to make a single triangle.

Input

The length of the segment L. 4 <= L <= 2000000000.

Output

The required number of parts.

Time limit 1 second
Memory limit 128 MiB
Input example #1
6

Output example #1
3