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.

输入描述:

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

输出描述:

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