def gen():
    a = 1       # for all
    b = 1       # for blue
    while True:
        yield (a + 1) // 2, (b + 1) // 2
        a, b = 3 * a + 4 * b, 2 * a + 3 * b

def search(limit):
    for a, b in gen():
        if a > limit:
            return b

print(search(int(10 ** 12)))