Problems
Matrix Cypher
Matrix Cypher
Alice and Bob communicate via a matrix channel. Alice wants to send a message to Bob. She has a bitstring representing her message and performs a bitwise encoding algorithm: She starts with the identity matrix
$$
A = \begin{pmatrix}
1 & 0 \\
0 & 1
\end{pmatrix}
$$
and then reads the bitstring starting from the left-most bit. For each $0$-bit she multiplies the matrix $A$ from the right with
$$
\begin{pmatrix}
1 & 0 \\
1 & 1
\end{pmatrix}, i.e.~A = A \cdot
\begin{pmatrix}
1 & 0 \\
1 & 1
\end{pmatrix}
$$
For each $1$-bit she multiplies the matrix $A$ from the right with
$$
\begin{pmatrix}
1 & 1 \\
0 & 1
\end{pmatrix}, i.e.~A = A \cdot
\begin{pmatrix}
1 & 1 \\
0 & 1
\end{pmatrix}
$$
Then the result is transmitted.
Now Bob accidentally deleted the software to decrypt a message from Alice. Can you help him to rewrite it?
\InputFile
Consists of two lines, the $i$-th of them with two integers $a_{i_1}$ and $a_{i_2}~(0 \le a_{i_1}, a_{i_2} \le 2^{128} - 1$ for all $i~(1 \le i \le 2)$, where
$$
A = \begin{pmatrix}
a_{11} & a_{12} \\
a_{21} & a_{22}
\end{pmatrix}
$$
is the matrix containing the encoded message.
The bitstring representing the message consists of at most $120$ characters.
\OutputFile
Output the decoded bitstring.
Input example #1
2 1 3 2
Output example #1
010
Input example #2
18 29 13 21
Output example #2
10010101