from math import floor, sqrt
def main(n):
    ans = 0
    prime = [True] * (7500)
    x = [i for i in range(n + 1)]
    for i in range(4, 7500, 2):
        prime[i] = False
    j = 4
    while j <= n:
        k = j
        while k <= n:
            x[k] >>= 2
            k += j
        j *= 4
    i = 3
    while i * i < n:
        if prime[i]:
            w = i * i
            j = w

            while j * j <= n:
                prime[j] = False
                j += 2 * i

            j = w
            while j <= n:
                k = j
                while k <= n:
                    x[k] //= w
                    k += j
                j *= w
        i += 2
    for i in range(1, n + 1):
        ans += floor(sqrt(n / x[i]))
    print(ans)

n = int(input())
main(n)