import java.io.InputStream;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        Solver solver = new Solver(System.in, out);
        solver.solve();
        out.close();
    }
}
class Solver {
	Scanner sc;
	PrintWriter out;
    public Solver(InputStream in, PrintWriter out) {
    	sc = new Scanner(in);
    	this.out = out;
    }
    // ==================================================================
    int LEN = (int)('z' - 'a');		// 'n' を含めない
    public void solve() {
    	int N = Integer.parseInt(sc.next());
    	if(N == 1) {
    		out.println('n');
    		return;
    	}
    	char[] C = new char[LEN];
    	char c;
    	int a = 0;
    	for (int i = 0; i < LEN + 1; i++) {
			c = (char)('a' + i);
			if(c == 'n') {	a = 1;	continue;	}
			C[i - a] = c;
		}
    	int now = 0;
    	for (int i = 0; i < LEN; i++) {
    		for (int k = 0; k < LEN; k++) {
				for (int k2 = 0; k2 < LEN; k2++) {
					for (int l = 0; l < LEN; l++) {
						if(now != N - 1)	out.println("a" + C[i] + C[k] + C[k2] + C[l] + "a");
						else {	
							out.println("a" + C[i] + C[k] + C[k2] + C[l] + "an");
							return;
						}
						now++;
					}
				}
			}
		}
    }
}