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
p=3005
from math import sqrt as S 
def Sieve():
    l=[True]*p 
    i=2 
    while i*i<=p:
        if l[i]:
            for j in range(i*i,p,i):
                l[j]=False 
        i+=1 
    l[0]=l[1]=False
    return l 
    return [i for i,a in enumerate(l) if a]
isprime=Sieve()
#print(primes)
'''
almost_prime={}
for i in range(len(primes)):
    for j in range(len(primes)):
        if primes[i]*primes[j]<=3000 and primes[i]!=primes[j]:
            almost_prime[primes[i]*primes[j]]=1 
#print(almost_prime)'''
def alm(x):
    cnt=0 
    for i in range(2,int(S(x))+1):
        if x%i==0:
            if isprime[i]:
                cnt+=1 
            if i!=x//i:
                if isprime[x//i]:
                    cnt+=1 
    if isprime[x]:
        cnt+=1 
    return cnt==2
    
psum=[0]*3005 
for i in range(2,p):
    if alm(i):
        psum[i]=psum[i-1]+1 
    else:
        psum[i]=psum[i-1] 
n=int(input())
print(psum[n])
