Problem2340--log2(N)

2340: log2(N)

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Time Limit : 1.000 sec  Memory Limit : 128 MB

SubmitSolved: 6Submit Num: 12Statistics

Description

Time Limit: 2 sec / Memory Limit: 1024 MB

Score : 200200 points

Problem Statement

Given a positive integer NN, find the maximum integer kk such that 2^k \le N2k≤N.

Constraints

  • NN is an integer satisfying 1 \le N \le 10^{18}1≤N≤1018.

Input

Input is given from Standard Input in the following format: 
NN

Output

Print the answer as an integer.

Sample Input Copy 

6

Sample Output Copy 

2

HINT

  • k=2 satisfies 2^2=4 \le 622=4≤6.
  • For every integer kk such that k \ge 3k≥3, 2^k > 62k>6 holds.

Therefore, the answer is k=2k=2.

Source/Category

AtCoder 
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