def get_prime(n):
    sieve = [True] * (n + 1) 
    i = 2
    while i * i <= n: 
        if sieve[i]:
            for j in range(i * i, n + 1, i):
                sieve[j] = False
        i += 1
    return [i for i in range(2, n + 1) if sieve[i]]

n = int(input())
l = get_prime(1000)
# print(l)
for i in range(2**20):
    tt = 1
    cnt = 0
    for j in range(20):
        #print(i,j)
        if i>>j & 1:
            cnt += 1
            tt *= l[j]
    else:
        if n < tt:
            print(cnt)
            exit()