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 primeFactors(n):
    # Print the number of two's that divide n
    primes = []
    if n%2==0:
        primes.append(2)
    while n % 2 == 0:

        n = n // 2

    # n must be odd at this point
    # so a skip of 2 ( i = i + 2) can be used
    for i in range(3,n, 2):

        # while i divides n , print i ad divide n
        if n%i==0:
            primes.append(i)
        while n % i == 0:

            n = n // i

            # Condition if n is a prime
    # number greater than 2
    if n!=0 and n!=1:
        primes.append(n)

    return primes
count=0
for i in range(2,n+1):

    if len(primeFactors(i))==2:
        count+=1
print(count)