#!python3



import sys

iim = lambda: list(map(int, sys.stdin.readline().rstrip().split()))



def get_factor(N):

    N1 = N + 2

    A = [2, 0] * (N1//2)



    for i in range(3, N1, 2):

        if A[i]:

            continue

        for j in range(i, N1, 2*i):

            A[j] = i



    def factor(n):

        i = 0

        ans = []



        while n & 1 == 0:

            i += 1

            n >>= 1

        if i:

            ans.append((2, i))



        while n > 1:

            a = A[n]

            i = 1

            while True:

                n //= a

                b = A[n]

                if a != b:

                    ans.append((a, i))

                    b = a

                    break

                i += 1



        return ans





    return factor



def resolve():

    N = int(sys.stdin.readline())



    f = get_factor(N)



    ans = 0

    for i in range(1, N):

        num = 1

        #print(i, f(i))

        for a, b in f(i):

            num *= b + 1

        ans += num

    print(ans)

if __name__ == "__main__":

    resolve()

#!python3



import sys

iim = lambda: list(map(int, sys.stdin.readline().rstrip().split()))



def resolve():

    N = int(sys.stdin.readline())

    N1 = N - 1



    ans = 0

    for i in range(1, N):

        ans += N1//i

    print(ans)

if __name__ == "__main__":

    resolve()

#!python3
import sys

iim = lambda: list(map(int, sys.stdin.readline().rstrip().split()))


def get_factor(N):
    N1 = N + 2
    A = [2, 0] * (N1 // 2)
    for i in range(3, N1, 2):
        if A[i]:
            continue
        for j in range(i, N1, 2 * i):
            A[j] = i

    def factor(n):
        i = 0
        ans = []
        while n & 1 == 0:
            i += 1
            n >>= 1
        if i:
            ans.append((2, i))
        while n > 1:
            a = A[n]
            i = 1
            while True:
                n //= a
                b = A[n]
                if a != b:
                    ans.append((a, i))
                    b = a
                    break
                i += 1
        return ans

    return factor


def resolve():
    N = int(sys.stdin.readline())
    f = get_factor(N)
    ans = 0
    for i in range(1, N):
        num = 1
        # print(i, f(i))
        for a, b in f(i):
            num *= b + 1
        ans += num
    print(ans)


if __name__ == "__main__":
    resolve()

#!python3
import sys

iim = lambda: list(map(int, sys.stdin.readline().rstrip().split()))


def resolve():
    N = int(sys.stdin.readline())
    N1 = N - 1
    ans = 0
    for i in range(1, N):
        ans += N1 // i
    print(ans)


if __name__ == "__main__":
    resolve()

-def get_factor(N): -    N1 = N + 2 -    A = [2, 0] * (N1 // 2) -    for i in range(3, N1, 2): -        if A[i]: -            continue -        for j in range(i, N1, 2 * i): -            A[j] = i - -    def factor(n): -        i = 0 -        ans = [] -        while n & 1 == 0: -            i += 1 -            n >>= 1 -        if i: -            ans.append((2, i)) -        while n > 1: -            a = A[n] -            i = 1 -            while True: -                n //= a -                b = A[n] -                if a != b: -                    ans.append((a, i)) -                    b = a -                    break -                i += 1 -        return ans - -    return factor - - -    f = get_factor(N) +    N1 = N - 1 -        num = 1 -        # print(i, f(i)) -        for a, b in f(i): -            num *= b + 1 -        ans += num +        ans += N1 // i