def weekday(year, month, day):
    if month in [1, 2]:
        year -= 1
        month += 13
    else:
        month += 1

    aa = int(year * 365.25)
    bb = int(month * 30.6)
    cc = year // 400
    dd = year // 100
    ee = aa + bb + cc + day - dd - 429
    ff = ee // 7 * 7
    return ee - ff


def main():
    n = int(input())
    ans = 0
    for y in range(2015, n + 1):
        ans += weekday(y, 7, 23) == 2
    print(ans)
    
if __name__ == '__main__':
    main()