// editor11
import java.util.*;
import java.util.stream.*;

class Main {
    public static void main(String[] Apple) {
        Scanner sc = new Scanner(System.in);
        
        if(!sc.hasNextLine()) {
            System.out.println("Invalid input");
            return;
        }
        String str = sc.nextLine().toLowerCase().trim();
        
        if(str.isEmpty() || str.length > 100) {
            System.out.println("Invalid input");
            return;
        }
        
        if(!str.matches("[a-z]+")) {
            System.out.println("Invalid input");
            return;
        }
        
        char[] ch = str.toCharArray();
        Arrays.sort(ch);
        String sorted = new String(ch);
        
        Set<Character> seen = new HashSet<>();
        Set<Character> dupl = new HashSet<>();
        
        for(int i = 1; i<sorted.length(); i++)
            if(sorted.charAt(i) == sorted.charAt(i - 1))
                dupl.add(sorted.charAt(i));
            
        if(dupl.isEmpty())
            System.out.println("None");
        else {
            dupl.stream()
                .forEach(s -> System.out.print(s + " "));
                System.out.println();
        }
        
        Set<Character> current = new HashSet<>();
        
        for(char c : sorted.toCharArray()) current.add(c);
        
        for(char alpha = 'a'; alpha <= 'z'; alpha++) {
            if(!current.contains(alpha))
                System.out.print(alpha + " ");
        }
    }
}