Progressions#167
The people of Progressland took their leader's slogan, "More progressions — good and varied," quite literally and decided to count how many different progressions they could think of. Luckily, they only know about strictly increasing arithmetic progressions of integers in the range from to , and each progression must start from the sacred number and have at least two elements. Unfortunately, they lack sufficient skills to solve the problem. Help them!
The first line contains a single integer (0 \leq N \leq 10^{12}).
Print a single integer — the number of distinct finite strictly increasing integer arithmetic progressions that begin with zero and are entirely within the range from to , inclusive. Each progression must have at least two different integers. Progressions with different numbers of terms are considered distinct.
Example 1