{"raw_statement":[{"iden":"problem statement","content":"You are given strings $s$ and $t$ of length $N$ consisting of `0` and `1`. Determine whether it is possible to make $s$ match $t$ by performing the following operation at least $0$ and at most $N+1$ times, and if possible, show one such sequence of operations.\nOperation: Perform the following in order.\n\n1.  Choose integers $a$ and $b$ satisfying $1 \\le a,b \\le N$ and $|a-b|=1$\n2.  Append the $a$\\-th character from the beginning of $s$ to the end of $s$\n3.  Remove the $b$\\-th character from the beginning of $s$ and concatenate the remaining characters in their original order\n\nYou are given $T$ test cases; find the answer for each of them."},{"iden":"constraints","content":"*   $1 \\le T \\le 10^{5}$\n*   $2 \\le N \\le 2 \\times 10^{5}$\n*   $s$ and $t$ are strings of length $N$ consisting of `0` and `1`.\n*   The sum of $N$ over all test cases is at most $2 \\times 10^{5}$."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$T$\n$\\text{case}_1$\n$\\text{case}_2$\n$\\vdots$\n$\\text{case}_T$\n\nEach test case is given in the following format:\n\n$N$\n$s$\n$t$"},{"iden":"sample input 1","content":"3\n5\n00101\n00010\n2\n01\n01\n2\n00\n11"},{"iden":"sample output 1","content":"1\n2 3\n0\n-1\n\nIn the first test case, $s$ is `00101` and $t$ is `00010`.\n\n*   By choosing $2$ and $3$ as $a$ and $b$, appending the $2$\\-nd character `0` to the end of $s$, and then removing the $3$\\-rd character, we can make $s$ and $t$ match.\n*   Note that the integers $a$ and $b$ chosen in the operation must satisfy $|a-b|=1$.\n\nIn the second test case, $s$ and $t$ can be made to match with zero operations.\nIn the third test case, no matter how the operations are performed, $s$ and $t$ cannot be made to match."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}