human
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
def m What is a Python program to find the amount of almost prime numbers which are between 1 and n, inclusive?
assistant
#Here is Python program to find the amount of almost prime numbers which are between 1 and n, inclusive.
ain():
    def ch(n):
        d = 2
        s = set()
        while n != 1:
            if n % d == 0:
                n = n // d
                s.add(d)
            else:
                d += 1
        return len(s)

    n = int(input())
    cnt = 0
    for i in range(1, n+1):
        if ch(i) == 2:
            cnt += 1
    print(cnt)

if __name__ == '__main__':
    main()