Contest Duration: - (local time) (100 minutes) Back to Home
A - Exponential Plant /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 1 \leq H \leq 10^{9}
• 入力は全て整数である。

### 入力

H


### 入力例 1

54


### 出力例 1

6


### 入力例 2

7


### 出力例 2

4


### 入力例 3

262144


### 出力例 3

19


Score : 100 points

### Problem Statement

Takahashi is growing a plant. Its height at the time of germination is 0\,\mathrm{cm}. Considering the day of germination as day 0, its height increases by 2^i\,\mathrm{cm} day i's night (0 \le i).

Takahashi's height is H\,\mathrm{cm}.

Every morning, Takahashi measures his height against this plant. Find the first day such that the plant's height is strictly greater than Takahashi's height in the morning.

### Constraints

• 1 \leq H \leq 10^{9}
• All input values are integers.

### Input

The input is given from Standard Input in the following format:

H


### Output

Print an integer representing the first day such that the plant's height is greater than Takahashi's height in the morning.

### Sample Input 1

54


### Sample Output 1

6


The plant's height in the mornings of days 1, 2, 3, 4, 5, 6 will be 1\,\mathrm{cm}, 3\,\mathrm{cm}, 7\,\mathrm{cm}, 15\,\mathrm{cm}, 31\,\mathrm{cm}, 63\,\mathrm{cm}, respectively. The plant becomes taller than Takahashi in the morning day 6, so print 6.

### Sample Input 2

7


### Sample Output 2

4


The plant's height will be 7\,\mathrm{cm} in the morning of day 3 and 15\,\mathrm{cm} in the morning day 4. The plant becomes taller than Takahashi in the morning of day 4, so print 4. Note that, in the morning of day 3, the plant is as tall as Takahashi, but not taller.

### Sample Input 3

262144


### Sample Output 3

19