import java.util.Scanner;

public class Collection {
    String[] strings;

    private static Collection ourInstance = new Collection();

    public static Collection getInstance() {
        return ourInstance;
    }

    private Collection() {
    }

    public void readConsole(){
        System.out.println("Enter String:");
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();

        strings = s.split("\\s");
    }

    public String sameLetters(){
        try {
            String lettersOutput = new String();
            for (int i = 0; i < strings[0].length(); i++) {
                char c = strings[0].charAt(i);
                if (strings[1].indexOf(c) != -1 && strings[2].indexOf(c) != -1 && lettersOutput.indexOf(c) == -1)
                    lettersOutput += strings[0].charAt(i);
            }
            return lettersOutput;
        }
        catch (IndexOutOfBoundsException e){
                return "There are not enough strings to find similar letters";
            }
    }

    public String[] getStrings(){
        return strings;
    }

    @Override
    public String toString(){
        String result = new String();
        for (int i = 0; i < strings.length; i++){
            result += strings[i] + "\n";
        }
        return result;
    }
}