Count primes#1126

Count primes

1 second
128 megabytes
Medium

Count the number of prime numbers in the given interval [l, r] (0 \leq l \leq r \leq 2147483647, r - l \leq 10^6).

Input

Two integers and .

Output

Print the number of primes in the interval [l, r].

Examples

Example 1

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