def is_leap(n):
    if n % 4 == 0 and n % 100 != 0 and n % 400 == 0:
        return True
    else:
        return False

# 2014/7/23(Wed)
N = int(input())

weds = 0
days = 0
for i in range(2014, N+1):
    if is_leap(i):
        days += 366
    else:
        days += 365
    if days % 7 == 0:
        weds += 1
print(weds)