Consecutive Sum (Financial Engineer Intern)

Given num, count the distinct ways to write num as a sum of at least two consecutive positive integers.

输入格式

A single integer, 1≤num≤10¹².

输出格式

Output the number of representations.

样例 1

输入：

15

输出：

3

样例 2

输入：

2

输出：

0

样例 3

输入：

9

输出：

2

样例说明

15 has three: 1+2+3+4+5, 4+5+6, 7+8; 2 has none; 9 has two: 2+3+4, 4+5.