Of three prime numbers#7673

Of three prime numbers

0.5 seconds
64 megabytes
Medium

Determine how many natural numbers within the range have a prime factorization consisting of exactly prime factors.

Input

A single line containing two integers and , separated by a space, where 1 \leq A \leq B \leq 10000000.

Output

A single line with one integer: the count of numbers in the specified range that have exactly prime factors.

Examples

Example 1

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Example 2

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