package com.company;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int start = Integer.parseInt(scanner.nextLine());
        int end = Integer.parseInt(scanner.nextLine());
        String pattern = "abcde";
        boolean found = false;
        for (int i = 0; i < 5; i++) {
            for (int j = 0; j < 5; j++) {
                for (int k = 0; k < 5; k++) {
                    for (int l = 0; l < 5; l++) {
                        for (int m = 0; m < 5; m++) {
                            String current = "" + pattern.charAt(i) + pattern.charAt(j) + pattern.charAt(k) + pattern.charAt(l) + pattern.charAt(m);

                            String unique = "" + current.charAt(0);
                            for (int f = 1; f < 5; f++) {
                                if (unique.indexOf(current.charAt(f)) == -1) {
                                    unique = unique + current.charAt(f);
                                }
                            }
                            int add = 0;
                            int sum = 0;
                                for (int f = 0; f < unique.length(); f++) {
                                    switch (unique.charAt(f)) {
                                        case 'a':
                                            add = 5;
                                            break;
                                        case 'b':
                                            add = -12;
                                            break;
                                        case 'c':
                                            add = 47;
                                            break;
                                        case 'd':
                                            add = 7;
                                            break;
                                        case 'e':
                                            add = -32;
                                            break;
                                    }
                                    sum += (f + 1) * add;
                                }
                                if (sum >= start && sum <= end) {
                                    System.out.print(current + " ");
                                    found = true;
                                }
                        }
                    }
                }
            }
        }
        if (!found){
            System.out.println("No");
        }
    }
}