def compute_cycle_count():
    count = 0
    for y in range(400):
        a = y + y // 4 - y // 100
        if a % 7 == 3:
            count += 1
    return count

cycle_count = compute_cycle_count()

n = int(input())

if n < 2015:
    print(0)
else:
    start = 2015
    end = n
    total_years = end - start + 1
    full_cycles = total_years // 400
    remaining = total_years % 400
    count = full_cycles * cycle_count

    # Check remaining years
    for y in range(start + full_cycles * 400, end + 1):
        a = y + y // 4 - y // 100 + y // 400
        if a % 7 == 3:
            count += 1
    print(count)