Progressions
The people of Progressland have taken their leader's slogan, "More progressions - good and varied," quite literally and are eager to count all the progressions they can create. Fortunately, they are only interested in strictly increasing integer arithmetic progressions that start at the sacred number 0 and are contained within the range from 0 to N. Each progression must have at least two elements. However, they need some help to solve this problem. Can you assist them?
**Input**: The first line of the input contains a single integer N (0 <= N <= 10^12).
**Output**: The output should be a single integer representing the number of distinct strictly increasing finite integer arithmetic progressions that begin with zero and are entirely within the range from 0 to N, inclusive. Each progression must consist of at least two different integers. Progressions with different numbers of terms are considered distinct.