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
prime=[2,3,5,7,11]

def create_list(n):
    global prime
    for x in range(prime[-1]+2,n+1,2):
        notPrime=False
        hold=int(x**0.5)+1
        for j in prime:
            if j>hold:
                break
            if x%j==0:
                notPrime=True
                break
        if notPrime==False:
            prime.append(x)
    #print(len(prime))

def factors(n):
    [z,count]=[2,0]
    while z*z<= n:
        if n%z==0:
            count+=1
            while (n%z==0):
                n//=z
        z+=1
    if n>1:count+=1
    if count==2:return 1
    return 0

def main():
    mode="filee"
    if mode=="file":f=open("test.txt","r")
    #f.readline()
    #input()
    get = lambda :[int(x) for x in (f.readline() if mode=="file" else input()).split()]
    [n]=get()
    if n<=5:
        print("0")
        return
    create_list(3000)
    count=0
    for i in range(6,n+1):
        if i in prime:
            continue
        count+=factors(i)
    print(count)

    if mode=="file":f.close()


if __name__=="__main__":
    main()
