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
# Python program to print all primes smaller than or equal to
# n using Sieve of Eratosthenes

def SieveOfEratosthenes(n):
	
	# Create a boolean array "prime[0..n]" and initialize
	# all entries it as true. A value in prime[i] will
	# finally be false if i is Not a prime, else true.
	li = []
	prime = [True for i in range(n+1)]
	p = 2
	while (p * p <= n):
		
		# If prime[p] is not changed, then it is a prime
		if (prime[p] == True):
			
			# Update all multiples of p
			for i in range(p * 2, n+1, p):
				prime[i] = False
		p += 1
	
	# Print all prime numbers
	for p in range(2, n):
		if prime[p]:
			li.append(p)
	return li

# driver program
if __name__=='__main__':
	n = 3000
	li = (SieveOfEratosthenes(n))
	num = int(input())
	primes = 0
	for i in range(2,num+1):
		count = 0
		for j in li:
			if(count>2 or j>i):
				break
			if(i%j == 0):
				count+=1
		if(count==2):
			primes+=1
	print(primes)
			