#P3653. 小清新数学题

    ID: 2663 远端评测题 3000ms 125MiB 尝试: 0 已通过: 0 难度: 8 上传者: 标签>O2优化枚举,暴力素数判断,质数,筛法前缀和

小清新数学题

Description

Let's keep the problem simple.

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

You are asked to compute i=lrμ(i)\sum_{i=l}^r \mu(i).

Input Format

One line contains two integers l,rl,r.

Output Format

One line contains one integer representing the answer.

1 233
-1
99999999999899999 99999999999999999
421

Hint

For 10%10\% of the testdata, l,r106l,r \leq 10^6.

For 30%30\% of the testdata, l,r1012l,r \leq 10^{12}.

For 100%100\% of the testdata, 1lr10181 \leq l \leq r \leq 10^{18}, rl105r-l \leq 10^5.

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