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.

Examples

Input

10


Output

2


Input

21


Output

8
from math import sqrt


def is_prime(n):
    if n < 2:
        return False
    for i in range(2, int(sqrt(n)) + 1):
        if n % i == 0:
            return False
    return True


def is_almost_prime(n):
    s = set()
    for i in range(2, int(sqrt(n)) + 1):
        if n % i == 0:
            if is_prime(i):
                s.add(i)
            if is_prime(n // i):
                s.add(n // i)
    if len(s) == 2:
        return True
    return False

n = int(input())
ans = 0
for i in range(6, n + 1):
    if is_almost_prime(i):
        ans += 1
print(ans)