B. Amusing numbers
time limit per test
1 second
memory limit per test
512 megabytes
input
standard input
output
standard output

Bulat is fond of mathematics and already has solved a lot of problems. He thought, that he would be able to solve any problem, but his teacher gave him very interesting problem.

Let's call integer n amusing, if two conditions hold:

  • n is composite
  • Number of divisors of n is a prime number

Now Bulat want's to answer the question: how many amusing numbers are there from l to r, inclusive? This problem seems very difficult for him, so he asks for your help.

Input

Input consists of two integers l and r (1 ≤ l ≤ r ≤ 1014).

Output

Output single integer: number of amusing number from l to r inclusive.

Examples
Input
1 9
Output
2
Input
3 6
Output
1
Input
6 9
Output
1