let genSafeWord =
    let rec num2alp num =        
        match num with
        | 0   -> ""
        | num ->
            let alpSize   = ('z' |> int) - ('a' |> int)
            let alpOffset = ('a' |> int) - 1
            let n = 
                match num%alpSize with
                | 0 -> alpSize
                | n -> n
            let s = (n + alpOffset) |> char |> string
            match n with
            | x when x = num -> s
            | x              -> num2alp((num - n) / alpSize) + s   
    let cnt=ref 1 
    let genWord startCharacter =
        let newWord = startCharacter + (num2alp cnt.Value)
        incr cnt
        newWord                            
    (fun (preWord:string) ->
        let preLastCharacter = preWord.ToCharArray() |> Array.last |> string        
        let newWord = genWord preLastCharacter
        match newWord.ToCharArray()|> Array.last |> string with
        | "n" -> genWord preLastCharacter
        |  _  -> newWord)
        
let genOutWord (preWord:string) =
    let preLastCharacter = preWord.ToCharArray() |> Array.last |> string
    preLastCharacter + "n"
    

let n = stdin.ReadLine() |> int

Seq.unfold(fun (word,cnt)->    
    match cnt = (n-1) with
    | true -> 
        let nextWord = genOutWord word
        Some(word, (nextWord, cnt + 1))
    | _    ->
        let nextWord = genSafeWord word
        Some(word, (nextWord, cnt + 1))) ("a", 0)
|> Seq.skip 1
|> Seq.take n
|> Seq.iter(printfn "%s")