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
def multiple(i):
    j = i 
    while j <= n:
        yield j
        j += i
def find_factor(n):
    divisor = []
    for i in range(1,int(n**(1/2))+1):
        if n%i == 0:
            divisor.append(i)
            divisor.append(n//i)
    return set(divisor)
count = 0
n = int(input())
prime = [i for i in range(2,n+1)]
true_prime = []
while len(prime) > 0:
    # print(prime[0])
    true_prime.append(prime[0])
    cross = [a for a in multiple(prime[0])]
    prime = [i for i in prime if i not in cross]
    
prime = [i for i in range(2,n+1)]
for n in prime:
    factor = find_factor(n)
    count = count + 1 if len([i for i in factor if i in true_prime]) == 2 else count

print(count)
    