Almost Prime

2000ms

262144K

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:

Input contains one integer number n (1 ≤ n ≤ 3000).

Output:

Output the amount of almost prime numbers between 1 and n, inclusive.

Sample Input:

Sample Output:

Sample Input:

Sample Output:

Informação

Provedor Codeforces

Código CF26A