N = int(input())
day = 0
remain = N - 2014
ans = 0

mul = remain // 2800
ans += mul * 399
remain %= 2800

for i in range(remain):
    y = 2015 + i
    if y % 400 == 0:
        day += 366
    elif y % 100 == 0:
        day += 365
    elif y % 4 == 0:
        day += 366
    else:
        day += 365
    if day % 7 == 0:
        ans += 1
   
print(ans)