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
if __name__ =="__main__":
	n = int(input())
	blank = 0
	prime = 1
	oprime = 2
	aprime = 3
	naprime = 4
	count = 0
	states = [blank for _ in range(3001)]
	states[0] = naprime
	states[1] = naprime
	for i in range(2,3001,1):
		if not states[i]==blank:
			continue
		
		states[i] = prime
		for j in range(2*i,3001,i):
			if states[j]==oprime:
				states[j] = aprime
			elif states[j] == aprime:
				states[j] = naprime
			elif states[j] == naprime:
				states[j] = naprime
			elif states[j] == blank:
				states[j] = oprime
				
				
				
	for i in range(1,n+1,1):
		if states[i]==aprime:
			count += 1
	print(count)