{"problem":{"name":"I hate 1","description":{"content":"You are given a positive integer $N$. A set $S$ of positive integers between $1$ and $N$ (inclusive) is called a **good set** if it satisfies the following condition: *   For every pair of elements $","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"arc198_a"},"statements":[{"statement_type":"Markdown","content":"You are given a positive integer $N$. A set $S$ of positive integers between $1$ and $N$ (inclusive) is called a **good set** if it satisfies the following condition:\n\n*   For every pair of elements $x$ and $y$ in $S$, the remainder when $x$ is divided by $y$ is not $1$.\n\nConstruct one good set with the maximum possible number of elements.\n\n## Constraints\n\n*   $1 \\le N \\le 2 \\times 10^{5}$\n\n## Input\n\nThe input is given from Standard Input in the following format:\n\n$N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"arc198_a","tags":[],"sample_group":[["5","2\n3 5\n\nFor example, $\\lbrace 3,5 \\rbrace$ and $\\lbrace 2 \\rbrace$ are good sets. On the other hand, $\\lbrace 2,3,5 \\rbrace$ and $\\lbrace 1,2,3,4,5 \\rbrace$ are not good sets.\nNo good set with three or more elements exists, so $\\lbrace 3,5 \\rbrace$ is one of the good sets with the maximum number of elements."],["2","1\n2"]],"created_at":"2026-03-03 11:01:13"}}