require 'date'
N = gets.to_i
M = 2015
Cycle = 400 * 7
def calc(y)
	a, res = 0, 0
	y.times do |i|
		a += Date.leap?(M + i) ? 2 : 1
		res += 1 if a % 7 == 0
	end
	res
end

years = N - M + 1
ans = calc(Cycle) * (years / Cycle) + calc(years % Cycle)
puts ans