Description

Given $L,R$, please compute the number of primes in the interval $[L,R]$.

$1\leq L\leq R < 2^{31}$，$R-L\leq 10^6$。

Input Format

The first line contains two positive integers $L$ and $R$.

Output Format

One line containing a single integer, the number of primes in the interval.

2 11

5

Hint

Translated by ChatGPT 5