fun main(args: Array<String>) = panasonic2020d()

fun panasonic2020d() {
    val n = readLine()!!.toInt()

    val answer = mutableListOf<String>()

    val str = "a".repeat(n).toCharArray()

    for (i in 0 until n) {
        answer.add(str.joinToString(""))
        for (j in 0..i) {
            str[str.lastIndex - i] = 'b'
            if (i > 0) str[str.lastIndex - i + 1] = 'a'
        }
    }

    println(answer.joinToString(System.lineSeparator()))
}
