Problem Background

Time Limit: 3s

Friendly Reminder: https://www.luogu.com.cn/problem/P3601

Problem Description

Let's keep the problem simple.

We define the Möbius function $\mu(x)$. If each prime factor of $x$ appears only once, and there are $p$ prime factors, then $\mu(x) = (-1)^p$. Otherwise, $\mu(x) = 0$.

This problem requires you to calculate $\sum_{i=l}^r \mu(i)$.

Input Format

One line containing two integers $l, r$.

Output Format

One line containing one integer representing the answer.

Sample Input and Output

Sample Input #1

1 233

Sample Output #1

-1

Sample Input #2

99999999999899999 99999999999999999

Sample Output #2

421

Notes

For $10\%$ of the data, $l, r \leq 10^6$.

For $30\%$ of the data, $l, r \leq 10^{12}$.

For $100\%$ of the data, $1 \leq l \leq r \leq 10^{18}$, $r - l \leq 10^5$.

见题面 Input 部分

见题面 Output 部分