from math import isqrt

num, den, two = 1, 1, 2

def sum_of_digits(n):
    s = 0
    while n:
        s, n = s + n % 10, n // 10
    return s

def reciprocal():
    global num, den
    num, den = den, num

def add_number_to_fraction(x):
    global num
    num = den * x + num

g = int(input())
if g == 1:
    print(2)
elif g == 2:
    print(3)
else:
    given = g
    three = 3
    num = (given // three) * two
    a = num - two
    if given % three == 1:
        num += 1
    elif given % three == 2:
        num = num * 2 + 1
        den = 2
    given -= given % three
    reciprocal()
    while given > 3:
        if given % three != 1:
            add_number_to_fraction(1)
        else:
            add_number_to_fraction(a)
            a -= two
        reciprocal()
        given -= 1
    add_number_to_fraction(1)
    reciprocal()
    add_number_to_fraction(2)
    print(sum_of_digits(num))