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
from sys import stdin,stdout
from collections import Counter
from math import ceil
from bisect import bisect_left 
from bisect import bisect_right
import math

ai = lambda: list(map(int, stdin.readline().split()))
ei = lambda: map(int, stdin.readline().split())
ip = lambda: int(stdin.readline().strip())

def seive(n,li):
	prime = [True for i in range(n+1)]
	prime[0]=prime[1] = False
	for i in range(2,int(math.sqrt(n))+1):
		if prime[i]:
			for j in range(i*i,n+1,i):
				prime[j] = False
	for i in range(n+1):
		if prime[i]:
			li.append(i)
	return li

pf = seive(3000,[])
ans = 0
for i in range(1,ip()+1):
	c = 0
	for j in pf:
		if i%j == 0:
			c += 1
	if c == 2:
		ans += 1

print(ans)