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
n = int(input())

def primes(n):
    if n == 1:
        return False
    if n == 2 or n == 3:
        return True
    if n%6 == 5 or n%6 == 1:
        check = True
        for i in range(2,int((n+1)/2)):
            if n%i == 0:
                check = False
                break
        if check is True:
            return True
        else:
            return False
    return False

number = 0
i = 2 
while i <= n:
    count = 0
    for j in range(2,i):
        if i%j == 0:
            if primes(j) == True:
                count += 1
                if count > 2:
                    break
    if count == 2:
        number += 1
    i+=1

print(number)
    

