import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;

/**
 * Solution to Word Ladder
 * 
 * @author vanb
 */
public class wordladder_vanb
{
    /** Input. */
    private static Scanner sc;
    
    /** Output. */
    private static PrintStream ps;
    
    /**
     * Do it!
     */
    private void doit()
    {
        int n = sc.nextInt();
        
        // Use binary bits to determine which letter to change
        char word[] = "aaaaaaaaaa".toCharArray();
        for( int i=1; i<=n; i++ )
        {
            ps.println( new String( word ) );
            int index = 0;
            while( (i&(1<<index))==0 ) ++index;
            if( index>9 ) index = 5;
            ++word[index];
            if( word[index]>'z' ) word[index] = 'a';
        }
    }
        
    /**
     * Main.
     * 
     * @param args unused
     * @throws Exception
     */
    public static void main( String[] args ) throws Exception
    {
        sc = new Scanner( System.in );
        ps = System.out;
        
        new wordladder_vanb().doit();
    }

}