def fairfield(y, m, d):
	if m <= 2:
		y -= 1
		m += 12
	return 365 * y + y / 4 - y / 100 + y / 400 + 306 * (m + 1) / 10 + d - 428

def zeller(y, m, d):
	return fairfield(y, m, d) % 7

N = input()

num = 0
total = [0] * 2800
y, m, d = 2014, 7, 23
for i in xrange(2800):
	if zeller(y + i, m, d) == 3:
		num += 1
	total[i] = num

q = (N - y) / 2800
ans = total[N - y - 2800 * q] + total[2800 - 1] * q - 1
print ans