{"problem":{"name":"K-th Substring","description":{"content":"You are given a string $s$. Among the **different** substrings of $s$, print the $K$\\-th lexicographically smallest one. A substring of $s$ is a string obtained by taking out a non-empty contiguous pa","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"arc097_a"},"statements":[{"statement_type":"Markdown","content":"You are given a string $s$. Among the **different** substrings of $s$, print the $K$\\-th lexicographically smallest one.\nA substring of $s$ is a string obtained by taking out a non-empty contiguous part in $s$. For example, if $s$ $=$ `ababc`, `a`, `bab` and `ababc` are substrings of $s$, while `ac`, `z` and an empty string are not. Also, we say that substrings are different when they are different as strings.\nLet $X = x_{1}x_{2}...x_{n}$ and $Y = y_{1}y_{2}...y_{m}$ be two distinct strings. $X$ is lexicographically larger than $Y$ if and only if $Y$ is a prefix of $X$ or $x_{j} > y_{j}$ where $j$ is the smallest integer such that $x_{j} \\neq y_{j}$.\n\n## Constraints\n\n*   $1$ $≤$ $|s|$ $≤$ $5000$\n*   $s$ consists of lowercase English letters.\n*   $1$ $≤$ $K$ $≤$ $5$\n*   $s$ has at least $K$ different substrings.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$s$\n$K$\n\n## Partial Score\n\n*   $200$ points will be awarded as a partial score for passing the test set satisfying $|s|$ $≤$ $50$.\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"arc097_a","tags":[],"sample_group":[["aba\n4","b\n\n$s$ has five substrings: `a`, `b`, `ab`, `ba` and `aba`. Among them, we should print the fourth smallest one, `b`. Note that we do not count `a` twice."],["atcoderandatcodeer\n5","andat"],["z\n1","z"]],"created_at":"2026-03-03 11:01:14"}}