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
import sys
readline = lambda: sys.stdin.readline().rstrip()
write = sys.stdout.write

def sieve(n):
	res = [True] * (n+1)
	res[0] = res[1] = False
	for i in xrange(2, n+1):
		if i*i > n: break
		if not res[i]: continue
		for j in xrange(i*i, n+1, i): res[j] = False
	return res

def main(n):
	res, is_prime = 0, sieve(n)
	for i in xrange(1, n+1):
		if is_prime[i]: continue
		cur, count = i, 0
		for p in xrange(2, cur+1):
			if p*p > cur: break
			if not is_prime[p]: continue
			if cur%p==0: count += 1
			while cur%p==0: cur /= p
		if cur != 1: count += 1
		if count == 2: res += 1
	return res

n = int(readline())
write(str(main(n)))
