n = int(input())
ans = 0
for x in range(10):
	for y in range(10):
		if x == y: continue
		suki = 10 ** 9 + 1
		kirai = max(x, y)
		while suki - kirai > 1:
			targ = (suki + kirai) // 2
			if n * (x * targ + y) > targ * targ - 1:
				kirai = targ
			else:
				suki = targ
		ans += kirai - max(x, y)
print(ans)