Halving Until Zero

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given nonnegative n, repeatedly replace n with the integer quotient n/2 until it becomes zero. Count how many divisions are performed. Initially zero requires none.

Input

One nonnegative integer n.

Output

Print the number of integer halvings performed.

Subtasks

• Subtask 1 (20%): 0 <= n <= 7.
• Subtask 2 (30%): 0 <= n <= 1000000.
• Subtask 3 (50%): 0 <= n <= 1000000000000000000.

Examples

Example 1

Input

5

Output

3

Explanation

5 -> 2 -> 1 -> 0 takes three divisions.

Example 2

Input

0

Output

0

Explanation

Zero needs no operation.