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#P26A. Almost Prime
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ID: 9649
Type: RemoteJudge
2000ms
256MiB
Tried: 0
Accepted: 0
Difficulty: 3
Uploaded By:
Hydro
Tags> Almost Prime
Description
A number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.
Input contains one integer number n (1 ≤ n ≤ 3000).
Output the amount of almost prime numbers between 1 and n, inclusive.
Input
Input contains one integer number n (1 ≤ n ≤ 3000).
Output
Output the amount of almost prime numbers between 1 and n, inclusive.
10
21
2
8