def step(a: str) -> str:
    b = "".join(["1" if c == "0" else "0" for c in reversed(a)])
    return a + "0" + b


def fill(a: str, n: int) -> str:
    while len(a) < n:
        a = step(a)
    return a[:n]


def checksum(a: str) -> str:
    while len(a) % 2 == 0:
        xs = []
        for i in range(0, len(a), 2):
            if a[i] == a[i + 1]:
                xs.append("1")
            else:
                xs.append("0")
        a = "".join(xs)
    return a


def solve():
    assert step("1") == "100"
    assert step("0") == "001"
    assert step("11111") == "11111000000"

    with open("i16.txt") as f:
        d = f.read().strip()

    a = fill(d, 272)
    b = checksum(a)
    print(b)

    a = fill(d, 35651584)
    b = checksum(a)
    print(b)


if __name__ == "__main__":
    solve()