def solve(i, N=64):
    VS = [
        2 ** N,
        2 ** (N+1),
        (2 ** N) + 2 ** (N+1),
    ]

    if i % 3 == 0:
        return i // 3
    else:
        for v in VS:
            if (i + v) % 3 == 0:
                return (i + v) // 3

    #     return i + 2**N // 3
    # elif i + 2**(N+1) % 3 == 0:
    #     return i + 2**(N+1) // 3
    # elif (i + 2**N + 2**(N+1)) % 3 == 0:
    #     return (i + 2**N + 2**(N+1)) // 3


def make(x, N=64):
    r = x * 3
    while True:
        if r >= 2**N:
            r -= 2**N
        else:
            break
    return r


def test(x, N=64):
    solved = solve(make(x)) == x
    assert make(x) >= 0
    assert make(x) <= 2**N
    assert solved


result = str(solve(int(open('input.txt').read())))
open('output.txt', 'w').write(result)