import java.io.*;
import java.util.*;


public class Main_yukicoder701 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		int n = sc.nextInt();

		Random rnd = new Random();
		
		Set<Integer> hs = new HashSet<>();
		for (int i = 0; i < n; i++) {
			int tmp = rnd.nextInt(1_000_000_000) + 1;
			while (hs.contains(tmp)) {
				tmp = rnd.nextInt(1_000_000_000) + 1;
			}
			hs.add(tmp);
			
			pr.print('a');
			
			while (tmp > 0) {
				pr.print((char)('a' + tmp % 10));
				tmp /= 10;
			}
			
			if (i < n - 1) {
				pr.print('a');
			} else {
				pr.print('n');
			}
			pr.println();
		}
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(INPUT == null ? System.in : new ByteArrayInputStream(INPUT.getBytes()));
		pr = new Printer(System.out);

		solve();

//		pr.close();
		pr.flush();
//		sc.close();
	}

	static String INPUT = null;

	private static class Printer extends PrintWriter {
		Printer(OutputStream out) {
			super(out);
		}
	}
}