import sys
from itertools import permutations
input = sys.stdin.readline

n = int(input())

ans = 0
for a, b in permutations([*range(10)], 2):
	min_p = max(a, b) + 1
	if(min_p ** 2 >= n * (min_p * a + b) + 1):
		continue
	ok = min_p
	ng = 10 ** 9
	while(ng - ok > 1):
		p = (ok + ng) >> 1
		if(p ** 2 < n * (p * a + b) + 1):
			ok = p
		else:
			ng = p
	ans += ok - min_p + 1

print(ans)