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 Cf294 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[] nextArray(int n)
		{
			int arr[] = new int[n];
			int i;
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
			}
			return arr;
		}
		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 int[] nextIntArray(int n,HashMap<Integer,Boolean> map)
		{
			int i;
			int arr[] = new int[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
				map.put(arr[i],true);
			}
			return arr;
		}
		
		public long[] nextLongArray(int n)
		{
			int i;
			long arr[] = new long[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextLong();
			}
			return arr;
		}
		
		public double[] nextDoubleArray(int n)
		{
			int i;
			double arr[] = new double[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextDouble();
			}
			return arr;
		}
		
		public Integer[] IntegerArray(int n)
		{
			int i;
			Integer arr[] = new Integer[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
			}
			return arr;
		}
		
		public Long[] LongArray(int n)
		{
			int i;
			Long arr[] = new Long[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextLong();
			}
			return arr;
		}
		
		public Double[] DoubleArray(int n)
		{
			int i;
			Double arr[] = new Double[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextDouble();
			}
			return arr;
		}
		
		public ArrayList<ArrayList<Integer>> getGraph(int n,int m)
		{
			ArrayList<ArrayList<Integer>> g =new ArrayList<>();
			int i;
			for(i=0;i<=n;i++)
			{
				g.add(new ArrayList<>());
			}
			for(i=0;i<m;i++)
			{
				int x = nextInt();
				int y = nextInt();
				g.get(x).add(y);
				g.get(y).add(x);
			}
			return g;
		}
		
		public ArrayList<ArrayList<Integer>> getTree(int n)
		{
			ArrayList<ArrayList<Integer>> g =new ArrayList<>();
			int i;
			for(i=0;i<=n;i++)
			{
				g.add(new ArrayList<>());
			}
			for(i=0;i<n-1;i++)
			{
				int x = nextInt();
				int y = nextInt();
				g.get(x).add(y);
				g.get(y).add(x);
			}
			return g;
		}
	}
	
	public static int maxInt(int arr[])
	{
		int max = Integer.MIN_VALUE;
		for(int i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static int minInt(int arr[])
	{
		int min = Integer.MAX_VALUE;
		for(int i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	public static long maxLong(long arr[])
	{
		long max = Long.MIN_VALUE;
		for(long i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static long minLong(long arr[])
	{
		long min = Long.MAX_VALUE;
		for(long i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	public static double maxDouble(double arr[])
	{
		double max = Double.MIN_VALUE;
		for(double i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static double minDouble(double arr[])
	{
		double min = Double.MAX_VALUE;
		for(double i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	void merge(int arr[], int l, int m, int r) 
	{ 
		int n1 = m - l + 1; 
		int n2 = r - m; 
	  

		int L[] = new int [n1]; 
		int R[] = new int [n2]; 
	  

		for (int i=0; i<n1; ++i) 
		    L[i] = arr[l + i]; 
		for (int j=0; j<n2; ++j) 
		    R[j] = arr[m + 1+ j]; 
  
  
  

		int i = 0, j = 0; 
	  

		int k = l; 
		while (i < n1 && j < n2) 
		{ 
		    if (L[i] <= R[j]) 
		    { 
			arr[k] = L[i]; 
			i++; 
		    } 
		    else
		    { 
			arr[k] = R[j]; 
			j++; 
		    } 
		    k++; 
		} 

		while (i < n1) 
		{ 
		    arr[k] = L[i]; 
		    i++; 
		    k++; 
		} 
	  
   
		while (j < n2) 
		{ 
		    arr[k] = R[j]; 
		    j++; 
		    k++; 
		} 
	} 
  
    
	void sort(int arr[], int l, int r) 
	{ 
		if (l < r) 
		{ 
			int m = (l+r)/2; 
			sort(arr, l, m); 
			sort(arr , m+1, r); 
			merge(arr, l, m, r); 
		} 
	}
	
	static class Pair
	{
		int x,y;
		public Pair(int x,int y)
		{
			this.x = x;
			this.y = y;
		}
		public static Comparator<Pair> sortX = new Comparator<Pair>(){
			public int compare(Pair p1,Pair p2)
			{
				if(p1.x==p2.x)
				{
					return p1.y-p2.y;
				}
				return p1.x-p2.x;
			}
		};
		
		public static Comparator<Pair> sortY = new Comparator<Pair>(){
			public int compare(Pair p1,Pair p2)
			{
				if(p1.y==p2.y)
				{
					return p1.x-p2.x;
				}
				return p1.y-p2.y;
			}
		};
		
		
		public boolean equals(Object obj) 
		{
			if (obj == null) return false;
			if (!(obj instanceof Pair))
				return false;
			return (this.x == ((Pair) obj).x && this.y == ((Pair)obj).y);
		}

		public int hashCode()
		{
			if(x<0 || y<0)
			{
				return -5*x+-32*y;
			}
			return 5*(x+y);
		}
	}
	
	static class DPair
	{
		Pair s,d;
		public DPair(Pair s,Pair d)
		{
			this.s = s;
			this.d = d;
		}
		
		public boolean equals(Object obj) 
		{
			if (obj == null) return false;
			if (!(obj instanceof DPair))
				return false;
			return (this.s.x == ((DPair) obj).s.x && this.s.y == ((DPair) obj).s.y && this.d.x == ((DPair)obj).d.x && this.d.y == ((DPair) obj).d.y);
		}
		public int hashCode()
		{
			return 5*(s.x+s.y+d.x+d.y);
		}
	}
	
	static class DSU
	{
		public static int rank[],parent[];
		int n;
		HashMap<Integer,Integer> map = new HashMap<>();
		
		public DSU(int n)
		{
			rank = new int[n+1];
			parent = new int[n+1];
			this.n = n;
			makeSet(n);
		}
		
		public void makeSet(int n)
		{
			for(int i=1;i<=n;i++)
			{
				parent[i] = i;
				map.put(i,1);
			}
		}
		
		public static int find(int x)
		{
			if(parent[x]!=x)
			{
				parent[x] = find(parent[x]);
			}
			return parent[x];
		}
		
		public void union(int x,int y)
		{
			int xRoot = find(x);
			int yRoot = find(y);
			
			if(xRoot==yRoot)
			{
				return;
			}
			
			if(rank[xRoot] < rank[yRoot])
			{
				parent[xRoot] = yRoot;
				map.put(yRoot,map.getOrDefault(yRoot,1)+map.getOrDefault(xRoot,1));
				if(map.getOrDefault(xRoot,0)!=0)
				{
					map.remove(xRoot);
				}
			}
			else if(rank[yRoot] < rank[xRoot])
			{
				parent[yRoot] = xRoot;
				map.put(xRoot,map.getOrDefault(xRoot,1) + map.getOrDefault(yRoot,1));
				if(map.getOrDefault(yRoot,0)!=0)
				{
					map.remove(yRoot);
				}
			}
			else
			{
				parent[yRoot] = xRoot;
				rank[xRoot] = rank[xRoot] + 1;
				map.put(xRoot,map.getOrDefault(xRoot,1)+map.getOrDefault(yRoot,1));
				if(map.getOrDefault(yRoot,0)!=0)
				{
					map.remove(yRoot);
				}
			}
		}
	}
	
	public static void main(String args[]) throws Exception 
	{
		new Thread(null, new Cf294(),"Main",1<<27).start();
	}	
	
	
	public void run()	
	{
		InputReader in = new InputReader(System.in);
		PrintWriter w = new PrintWriter(System.out);
		int t = in.nextInt();
		while(t-->0)
		{
			int n = in.nextInt();
			HashMap<String,Integer> map = new HashMap<>();
			int count = 0;
			int i,j,k;
			String st[] = new String[n];
			for(i=0;i<n;i++)
			{
				String s = new String();
				s = in.next();
				st[i] = s;
				map.put(s,map.getOrDefault(s,0)+1);
			}
			if(map.size()==n)
			{
				w.println(0);
				for(i=0;i<n;i++)
				{
					w.println(st[i]);
				}
			}
			else
			{
				for(i=0;i<n;i++)
				{
					int c = map.get(st[i]);
					if(c!=1)
					{
						count+=c-1;
						map.put(st[i],1);
						
						while(c>1)
						{
							for(j=i+1;j<n;j++)
							{
								if(st[i].equals(st[j]))
								{
									String ns = new String();
									ns+=st[j].charAt(0);
									ns+=st[j].charAt(1);
									ns+=st[j].charAt(2);
									ns+="0";
									while(map.getOrDefault(ns,-1)!=-1)
									{
										char a = ns.charAt(3);
										a=(char)(a+1);
										ns="";
										ns+=st[j].charAt(0);
										ns+=st[j].charAt(1);
										ns+=st[j].charAt(2);
										ns+=a;
									}
									st[j] = ns;
									map.put(ns,1);
									c--;
								}
							}
						}
					}
				}
				//w.println(map);
				w.println(count);
				for(i=0;i<n;i++)
				{
					w.println(st[i]);
				}
			}
		}
		w.flush();
		w.close();
	}
}