import java.util.stream.*;
import java.util.*;

public class Main {
        static Random rand = new Random();
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        long start = System.currentTimeMillis();

        StringBuilder sb = new StringBuilder();
                
        Map answers = new HashMap<String,String>();
        char last = 'a';
        for(int i=0;i<n-1;i++){
            while(true){
                String s = randomWord(last);
                if(answers.containsKey(s)){continue;}
                answers.put(s,null);
                sb.append(s);
                sb.append("\r\n");
                last = s.charAt(s.length()-1);
                break;
            }
        }
        while(true){
            String s = randomWord(last);
            s = s.substring(0,s.length()-1) + "n";
            sb.append(s);
            sb.append("\r\n");
            break;
        }
         System.out.println(sb.toString());

        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }
    
    /**
     * c で始まる20文字以下の単語を返す
     */
    public static String randomWord(char c){
        StringBuffer sb = new StringBuffer();
        sb.append(c);
        int length = rand.nextInt(20);
        if(length==0) return String.valueOf(c);
        IntStream.range(0,length-1).forEach( i -> sb.append(randomAlphabet()));
        sb.append(randomAlphabetExceptN());
        return sb.toString();
    }
    
    public static char randomAlphabet(){
        return (char)(97 + rand.nextInt(26));
    }
    public static char randomAlphabetExceptN(){
        int n = rand.nextInt(25);
        if( n < 13){
            return (char)(97 + n);
        }else{
            return (char)(98 + n);
        }
    }
    
    
    
}