import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        char[] p = "abcdefghijklmopqrstuvwxyz".toCharArray();

        char last = 'a';

        for (int i = 0; i < n - 1; i++) {
            char[] mid = new char[18];
            for (int j = 0; j < 18; j++) {
                if ((i & (1<<j)) == 0) {
                    mid[j] = 'a';
                }
                else {
                    mid[j] = 'b';
                }
            }

            System.out.println(p[i%p.length] + String.valueOf(mid) + p[(i+1)%p.length]);
            last = p[(i+1)%p.length];
        }

        System.out.println(last + "n");
    }
}