import itertools
dovzina = int(input())
vsechisla = []
allpairs = []
praviln = 0

def gen_all_numbers():
    for i in itertools.product(['1', '2', '3', '4', '5', '6', '7', '8', '9', '0'], repeat=dovzina):
        chislo = ''.join(i)
        if chislo[0] != "0":
            vsechisla.append(int(chislo))

def get_all_pairs():
    allpairsgen = []
    allpairsgen.append(itertools.combinations(vsechisla, 2))
    for tup in allpairsgen:
        for item in tup:
            allpairs.append(item)

def vozak_kus(num1, num2):
    res = ""
    res_in_list = []
    for kakoeplusovat in range(1, dovzina + 1):
        strnum1 = str(num1)
        strnum2 = str(num2)
        polures = str(int(strnum1[-kakoeplusovat]) + int(strnum2[-kakoeplusovat]))
        if len(polures) >= 2:
            polures = polures[-1]
        res_in_list.insert(0, ((int(polures))))
    for i in range(len(res_in_list)):
        res = res + str(res_in_list[i])
    return int(res)

def standart_plus(num1, num2):
    return num1 + num2


gen_all_numbers()
get_all_pairs()

for i in allpairs:
    if vozak_kus(i[0], i[1]) == standart_plus(i[0], i[1]):
        praviln += 1


print(int("1" + "0" + "0" * dovzina) + praviln)