We are going to generate a sequence of integers in binary. Start with the sequence \begin{lstlisting}[language=C++] 0 1 - \end{lstlisting} Reflect it in the horizontal line, ascribe a zero to the numbers in the top half and a one to the numbers on the bottom and you will get \begin{lstlisting}[language=C++] 00 01 11 10 \end{lstlisting} Repeat this again, and you will have $8$ numbers \begin{lstlisting}[language=C++] 000 0 001 1 011 3 010 2 110 6 111 7 101 5 100 4 \end{lstlisting} The corresponding decimal values are shown on the right. These sequences are called Reflected Gray Codes for $1, 2$ and $3$ bits respectively. A Gray Code for $n$ bits is a sequence of $2n$ different $n$-bit integers with the property that every two neighboring integers differ in exactly one bit. A Reflected Gray Code is a Gray Code constructed in the way shown above. \InputFile The first line gives the number of test cases $t~(t \le 250000)$. Each test is a line with two integers: $n~(1 \le n \le 30)$ and $k~(0 \le k < 2^n)$. \OutputFile For each test case, output the integer that appears in position $k$ of the $n$-bit Reflected Gray Code.