{"problem":{"name":"Lunlun Number","description":{"content":"A positive integer $X$ is said to be a lunlun number if and only if the following condition is satisfied: *   In the base ten representation of $X$ (without leading zeros), for every pair of two adja","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc161_d"},"statements":[{"statement_type":"Markdown","content":"A positive integer $X$ is said to be a lunlun number if and only if the following condition is satisfied:\n\n*   In the base ten representation of $X$ (without leading zeros), for every pair of two adjacent digits, the absolute difference of those digits is at most $1$.\n\nFor example, $1234$, $1$, and $334$ are lunlun numbers, while none of $31415$, $119$, or $13579$ is.\nYou are given a positive integer $K$. Find the $K$\\-th smallest lunlun number.\n\n## Constraints\n\n*   $1 \\leq K \\leq 10^5$\n*   All values in input are integers.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$K$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc161_d","tags":[],"sample_group":[["15","23\n\nWe will list the $15$ smallest lunlun numbers in ascending order:  \n$1$, $2$, $3$, $4$, $5$, $6$, $7$, $8$, $9$, $10$, $11$, $12$, $21$, $22$, $23$.  \nThus, the answer is $23$."],["1","1"],["13","21"],["100000","3234566667\n\nNote that the answer may not fit into the $32$\\-bit signed integer type."]],"created_at":"2026-03-03 11:01:14"}}