def c_a_times_b_plus_c():

    N = int(eval(input()))

    ans = 0

    for a in range(1, N + 1):

        for b in range(N // a, 0, -1):

            if N - a * b >= 1:

                ans += 1

    return ans



print((c_a_times_b_plus_c()))

def c_a_times_b_plus_c():

    N = int(eval(input()))

    return sum((N - 1) // a for a in range(1, N))



print((c_a_times_b_plus_c()))
def c_a_times_b_plus_c():
    N = int(eval(input()))
    ans = 0
    for a in range(1, N + 1):
        for b in range(N // a, 0, -1):
            if N - a * b >= 1:
                ans += 1
    return ans


print((c_a_times_b_plus_c()))

def c_a_times_b_plus_c():
    N = int(eval(input()))
    return sum((N - 1) // a for a in range(1, N))


print((c_a_times_b_plus_c()))

-    ans = 0 -    for a in range(1, N + 1): -        for b in range(N // a, 0, -1): -            if N - a * b >= 1: -                ans += 1 -    return ans +    return sum((N - 1) // a for a in range(1, N))