Zhuangzi's Stick Problem

In the ancient text Zhuangzi, it is said: “A one-foot stick, each day take half of it, and it will last for ten thousand generations”. On day 1, there is a wooden stick of length $a$. Starting from day 2, every day the stick is cut in half, i.e. its length is updated to $\lfloor \frac{length}{2} \rfloor$. Determine on which day the stick's length will become exactly $1$.

inputFormat

The input consists of a single integer $a$ ($1 \leq a \leq 10^{18}$), representing the initial length of the stick.

outputFormat

Output the day number on which the stick's length becomes exactly $1$.

sample

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