Problem: A PIN code is a string that consists of exactly 4 digits. Examples of possible PIN codes: 7013, 0000 and 0990. Please note that the PIN code can begin with any digit, even with 0.

Polycarp has n (2 ≤ n ≤ 10) bank cards, the PIN code of the i-th card is p_i.

Polycarp has recently read a recommendation that it is better to set different PIN codes on different cards. Thus he wants to change the minimal number of digits in the PIN codes of his cards so that all n codes would become different.

Formally, in one step, Polycarp picks i-th card (1 ≤ i ≤ n), then in its PIN code p_i selects one position (from 1 to 4), and changes the digit in this position to any other. He needs to change the minimum number of digits so that all PIN codes become different.

Polycarp quickly solved this problem. Can you solve it?

Input

The first line contains integer t (1 ≤ t ≤ 100) — the number of test cases in the input. Then test cases follow.

The first line of each of t test sets contains a single integer n (2 ≤ n ≤ 10) — the number of Polycarp's bank cards. The next n lines contain the PIN codes p_1, p_2, ..., p_n — one per line. The length of each of them is 4. All PIN codes consist of digits only.

Output

Print the answers to t test sets. The answer to each set should consist of a n + 1 lines

In the first line print k — the least number of changes to make all PIN codes different. In the next n lines output the changed PIN codes in the order corresponding to their appearance in the input. If there are several optimal answers, print any of them.

Example

Input


3
2
1234
0600
2
1337
1337
4
3139
3139
3139
3139


Output


0
1234
0600
1
1337
1237
3
3139
3138
3939
6139

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;
import java.math.*;
import java.lang.*;

import static java.lang.Math.*;

public class Cf131 implements Runnable 
{
    static class InputReader 
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;
        private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }
        
        public int read()
        {
            if (numChars==-1) 
                throw new InputMismatchException();
            
            if (curChar >= numChars) 
            {
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                }
                catch (IOException e)
                {
                    throw new InputMismatchException();
                }
                
                if(numChars <= 0)               
                    return -1;
            }
            return buf[curChar++];
        }
    
        public String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }    
            return str;
        }
        public int nextInt() 
        {
            int c = read();
            
            while(isSpaceChar(c)) 
                c = read();
        
            int sgn = 1;
        
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            
            int res = 0;
            do
            {
                if(c<'0'||c>'9') 
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c)); 
        
            return res * sgn;
        }
        
        public long nextLong() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;
            
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }    
            while (!isSpaceChar(c));
                return res * sgn;
        }
        
        public double nextDouble() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') 
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') 
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
    
        public String readString() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = read();
            } 
            while (!isSpaceChar(c));
            
            return res.toString();
        }
    
        public boolean isSpaceChar(int c) 
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
    
        public String next()
        {
            return readString();
        }
        
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
    public static void main(String args[]) throws Exception 
    {
        new Thread(null, new Cf131(),"Main",1<<27).start();
    }
    
    static class Pair{
        int nod;
        int ucn;
        
        
        Pair(int nod,int ucn){
            this.nod=nod;
            this.ucn=ucn;
            
        }
        
    public static Comparator<Pair> wc = new Comparator<Pair>(){
        public int compare(Pair e1,Pair e2){
            
            //reverse order
            if (e1.ucn < e2.ucn) 
                return 1;  // 1 for swaping.
            else if (e1.ucn > e2.ucn) 
                return -1; 
            else{
                // if(e1.siz>e2.siz)
                //     return 1;
                // else
                //     return -1;
                return 0;
            } 
        }
    };	
    }

    public static long gcd(long a,long b){
        if(b==0)return a;
        else return gcd(b,a%b);
    }


    ////recursive BFS
    public static int bfsr(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,int[] pre){
        b[s]=true;
        int p = 0;
        int t = a[s].size();
        for(int i=0;i<t;i++){
            int x = a[s].get(i);
            if(!b[x]){
                dist[x] = dist[s] + 1;
                p+= (bfsr(x,a,dist,b,pre)+1);
            }
        }
        pre[s] = p;
        return p;
    }

//// iterative BFS
    public static int bfs(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,PrintWriter w){
        b[s]=true;
        int siz = 0;
        
        Queue<Integer> q = new LinkedList<>();
        q.add(s);
        while(q.size()!=0){
            int i=q.poll();
        //    w.println(" #"+i+"# ");
            Iterator<Integer> it =a[i].listIterator();
            int z=0;
            while(it.hasNext()){
                z=it.next();
               // w.println("#"+i+" "+z);
                if(!b[z]){
                //    w.println("* "+z+" *");
                    b[z]=true;
                    dist[z] = dist[i] + 1;
                 //   w.print("*");
                   // w.println(i+" "+z);
                    siz++;
                //    x.add(z);
                //    w.println("@ "+x.get(x.size()-1)+" @");
                    q.add(z);
                }
            }   
        
        }
        return siz;
    }







//////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////


    public void run()
    {
        InputReader sc = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        int defaultValue=0;
       

        int t = sc.nextInt();
        while(t-->0){
        
            int n = sc.nextInt();
            String[] a = new String[n];
            HashMap<String,Integer> hm = new HashMap<String,Integer>();
            for(int i=0;i<n;i++){
                a[i] = sc.next();
                hm.put(a[i],hm.getOrDefault(a[i], defaultValue)+1);
            }
           // Arrays.sort(a);
          //  for(int i=0;i<n;i++)w.println(a[i]);
            int ans = 0;
            for(int i=0;i<n;i++){
                int x = hm.getOrDefault(a[i],0);
                if(x>1){
                    ans+=(x-1);
                    hm.put(a[i],1);
                    int j=i+1;
                    char y = '0';
                    while(x>1){
                     //   w.println("# "+x);
                       if(a[i].equals(a[j])){
                            StringBuilder z = new StringBuilder(a[j]);
                            
                            z.setCharAt(0, y);
                            while(hm.getOrDefault(z.toString(),0)!=0){
                                y = (char)(y+1);
                                z.setCharAt(0, y);
                            }
                            y = (char)(y+1);
                            a[j] = z.toString();
                            hm.put(a[j],1);
                            x--;
                        }
                        
                        j++;
                    }
                }
            }
            w.println(ans);
            for(int i=0;i<n;i++)w.println(a[i]);
            
           
        }    
        w.flush();
        w.close();



        
        
    }

}