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();
                
        List answers = new ArrayList<String>();
        String last = "a";
        for(int i=0;i<n-1;i++){
            while(true){
                String s = randomWord(last);
                if(answers.contains(s)){continue;}
                answers.add(s);
                sb.append(s);
                sb.append("\r\n");
                last = s.substring(s.length()-1);
                break;
            }
        }
        while(true){
            String s = randomWord(last);
            if(answers.contains(s)){continue;}
            s = s.substring(0,s.length()-1) + "n";
            sb.append(s);
            sb.append("\r\n");
            break;
        }
        System.out.println(sb.toString());
    }
    
    /**
     * s で始まる20文字以下の単語を返す
     */
    public static String randomWord(String s){
        Random rand = new Random();
        StringBuffer sb = new StringBuffer(s);
        
        int length = rand.nextInt(20);
        if(length==0) return s;
        for(int i=0;i<length - 1;i++){
            sb.append(randomAlphabet());
        }
        sb.append(randomAlphabetExceptN());
        return sb.toString();
    }
    
    public static char randomAlphabet(){
        Random rand = new Random();
        return (char)(97 + rand.nextInt(26));
    }
    public static char randomAlphabetExceptN(){
        Random rand = new Random();
        int n = rand.nextInt(25);
        if( n < 13){
            return (char)(97 + n);
        }else{
            return (char)(98 + n);
        }
    }
    
    
    
}