{"problem":{"name":"Repsept","description":{"content":"Takahashi loves the number $7$ and multiples of $K$. Where is the first occurrence of a multiple of $K$ in the sequence $7,77,777,\\ldots$? (Also see Output and Sample Input/Output below.) If the seque","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc174_c"},"statements":[{"statement_type":"Markdown","content":"Takahashi loves the number $7$ and multiples of $K$.\nWhere is the first occurrence of a multiple of $K$ in the sequence $7,77,777,\\ldots$? (Also see Output and Sample Input/Output below.)\nIf the sequence contains no multiples of $K$, print `-1` instead.\n\n## Constraints\n\n*   $1 \\leq K \\leq 10^6$\n*   $K$ is an integer.\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":"abc174_c","tags":[],"sample_group":[["101","4\n\nNone of $7$, $77$, and $777$ is a multiple of $101$, but $7777$ is."],["2","\\-1\n\nAll elements in the sequence are odd numbers; there are no multiples of $2$."],["999983","999982"]],"created_at":"2026-03-03 11:01:14"}}