content: import java.util.*;
  import org.json.simple.JSONObject;
  
  class MapReduce
  {
     private LinkedHashMap intermediate;
     private JSONObject finalResult = new JSONObject();
     private int resultCount;
     MapReduce()
     {
        resultCount=0;
        finalResult = new JSONObject();
        intermediate=new LinkedHashMap();
     }
  
     JSONObject execute(JSONObject inputdata)
     {
        for(int i=0;i<inputdata.size();i++)
        {
           LinkedHashMap record=(LinkedHashMap)inputdata.get(i);
           mapper(record);
        }
  
        Iterator it = intermediate.entrySet().iterator();
        while (it.hasNext()) {
           Map.Entry pair = (Map.Entry)it.next();
           reducer((int)pair.getKey(), (HashSet)pair.getValue());
           it.remove();
        }
        return finalResult;
  
  
     }
     private void emit(LinkedHashMap obj)
     {
        finalResult.put(resultCount++,obj);
     }
     private void reducer(int key, HashSet value)
     {
        // Fill up the question mark in the reducer function!
        if(value.size()==2)
        {
           LinkedHashMap obj=new LinkedHashMap();
           obj.put("key",key);
           emit(obj);
        }
     }
     private void mapper(LinkedHashMap record)
     {
        String value=(String)record.get("value");
        int key=(int)record.get("key");
        emitIntermediate(key,value);
  
     }
     private void emitIntermediate(int key, String value)
     {
        if(!intermediate.containsKey(key))
           intermediate.put(key,new HashSet());
  
        HashSet temp=(HashSet)intermediate.get(key);
        temp.add(value);
        intermediate.put(key,temp);
     }
  }
  public class Main
  {
  
     public static void main(String []argh)
     {
        JSONObject inputdata= new JSONObject();
        Scanner sc=new Scanner(System.in);
        int Nr=sc.nextInt();
        int Ns=sc.nextInt();
        int []R=new int[Nr];
        int []S=new int[Ns];
        int c=0;
        for(int i=0;i<Nr;i++)
        {
  
           Map obj=new LinkedHashMap();
           R[i]=sc.nextInt();
           obj.put("value","R");
           obj.put("key",R[i]);
           inputdata.put(c,obj);
           c++;
        }
  
        for(int i=0;i<Ns;i++)
        {
           Map obj=new LinkedHashMap();
           S[i]=sc.nextInt();
           obj.put("value","S");
           obj.put("key",S[i]);
           inputdata.put(c,obj);
           c++;
        }
  
  
        MapReduce mapred= new MapReduce();
        JSONObject result=mapred.execute(inputdata);
  
        for(int i=0;i<result.size();i++)
        {
           LinkedHashMap record=(LinkedHashMap)result.get(i);
           System.out.println(record.get("key"));
  
        }
  
     }
  
  }
  