题目描述
Problem Background
It's not so much a sense of reluctance, what even is this chart...
——ReMiRiA
Although winning the championship is very happy, what even is this chart? Will it really be included??
——yoshiki
Problem Description
Fusu enjoys splitting natural numbers.
For a given positive integer \( n \), if \( n = i \times j \times k \), where \( i, j, k \) are positive integers, then the triplet \( (i, j, k) \) is called an excellent split of \( n \).
The triplet \( (i, j, k) \) is ordered. For example, for \( 2 = 1 \times 1 \times 2 = 1 \times 2 \times 1 = 2 \times 1 \times 1 \), we consider \( (1, 1, 2) \), \( (1, 2, 1) \), and \( (2, 1, 1) \) as three different excellent splits.
Now, Fusu wants to know, for \( n = 1, 2, 3 \ldots N \), what is the sum of all excellent splits of \( n \).
Formally, let \( f(n) \) denote the number of excellent splits of \( n \). You need to find \( \sum_{i = 1}^N f(i) \).
Input Format
The input consists of a single line containing an integer \( N \) (\( 1 \leq N \leq 10^{10} \)).
Output Format
Output a single integer representing the answer. Since the answer may be very large, you only need to output the remainder of this value divided by \( 2^{64} \).
Sample Input and Output
Sample Input #1
2
Sample Output #1
4
Sample Input #2
100
Sample Output #2
1471
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分