Solution.java

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.lang.reflect.*;


class Singleton{
private Singleton() {}
    public String str;
    private static Singleton instance = null;
    public static Singleton getSingleInstance() {
        if (instance == null) {
            instance = new Singleton();
        }
        return instance;
    }
}