import java.util.*;

public class Main {
	public static void main (String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		StringBuilder sb = new StringBuilder();
		char start = 'a';
		for (int i = 1; i < n; i++) {
		    sb.append(start).append(getStr(i)).append(start).append("\n");
		}
		sb.append("an");
		System.out.println(sb);
	}
	
	static StringBuilder  getStr(int x) {
	    StringBuilder sb = new StringBuilder();
	    for (int i = 0; i < 8; i++) {
	        sb.append((char)(x % 10 + 'a'));
	        x /= 10;
	    }
	    return sb;
	}
}