{"raw_statement":[{"iden":"problem statement","content":"Given is a positive even number $N$.\nFind the number of strings $s$ of length $N$ consisting of `A`, `B`, and `C` that satisfy the following condition:\n\n*   $s$ can be converted to the empty string by repeating the following operation:\n    *   Choose two consecutive characters in $s$ and erase them. However, choosing `AB` or `BA` is not allowed.\n\nFor example, `ABBC` satisfies the condition for $N=4$, because we can convert it as follows: `ABBC` → (erase `BB`) → `AC` → (erase `AC`) → `(empty)`.\nThe answer can be enormous, so compute the count modulo $998244353$."},{"iden":"constraints","content":"*   $2 \\leq N \\leq 10^7$\n*   $N$ is an even number."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$"},{"iden":"sample input 1","content":"2"},{"iden":"sample output 1","content":"7\n\nExcept `AB` and `BA`, all possible strings satisfy the conditions."},{"iden":"sample input 2","content":"10"},{"iden":"sample output 2","content":"50007"},{"iden":"sample input 3","content":"1000000"},{"iden":"sample output 3","content":"210055358"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}