{"problem":{"name":"1 2 1 3 1 2 1","description":{"content":"We define sequences $S_n$ as follows. *   $S_1$ is a sequence of length $1$ containing a single $1$. *   $S_n$ ($n$ is an integer greater than or equal to $2$) is a sequence obtained by concatenating","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc247_c"},"statements":[{"statement_type":"Markdown","content":"We define sequences $S_n$ as follows.\n\n*   $S_1$ is a sequence of length $1$ containing a single $1$.\n*   $S_n$ ($n$ is an integer greater than or equal to $2$) is a sequence obtained by concatenating $S_{n-1}$, $n$, $S_{n-1}$ in this order.\n\nFor example, $S_2$ and $S_3$ is defined as follows.\n\n*   $S_2$ is a concatenation of $S_1$, $2$, and $S_1$, in this order, so it is $1,2,1$.\n*   $S_3$ is a concatenation of $S_2$, $3$, and $S_2$, in this order, so it is $1,2,1,3,1,2,1$.\n\nGiven $N$, print the entire sequence $S_N$.\n\n## Constraints\n\n*   $N$ is an integer.\n*   $1 \\leq N \\leq 16$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc247_c","tags":[],"sample_group":[["2","1 2 1\n\nAs described in the Problem Statement, $S_2$ is $1,2,1$."],["1","1"],["4","1 2 1 3 1 2 1 4 1 2 1 3 1 2 1\n\n*   $S_4$ is a concatenation of $S_3$, $4$, and $S_3$, in this order."]],"created_at":"2026-03-03 11:01:13"}}