n = int(input())
count = 0
base_leap = (2014 // 4) - (2014 // 100) + (2014 // 400)  # Precomputed for 2014

for y in range(2015, n + 1):
    # Calculate the number of leap years from 2015 to y inclusive
    leap = (y // 4) - (y // 100) + (y // 400) - base_leap
    total_days = (y - 2014) * 365 + leap
    if total_days % 7 == 0:
        count += 1

print(count)