Contest Duration: - (local time) (100 minutes) Back to Home
D - Staircase Sequences /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 1 ≤ N ≤ 10^{12}
• N は整数

### 入力

N


### 入力例 1

12


### 出力例 1

4

• [12]
• [3, 4, 5]
• [-2, -1, 0, 1, 2, 3, 4, 5]
• [-11, -10, -9, \dots, 10, 11, 12]

4 個です。

### 入力例 2

1


### 出力例 2

2

• [1]
• [0, 1]

2 個です。

### 入力例 3

963761198400


### 出力例 3

1920


Score : 400 points

### Problem Statement

How many arithmetic progressions consisting of integers with a common difference of 1 have a sum of N?

### Constraints

• 1 ≤ N ≤ 10^{12}
• N is an integer.

### Input

Input is given from Standard Input in the following format:

N


### Sample Input 1

12


### Sample Output 1

4


We have four such progressions:

• [12]
• [3, 4, 5]
• [-2, -1, 0, 1, 2, 3, 4, 5]
• [-11, -10, -9, \dots, 10, 11, 12]

### Sample Input 2

1


### Sample Output 2

2


We have two such progressions:

• [1]
• [0, 1]

### Sample Input 3

963761198400


### Sample Output 3

1920