2
2 6 8 1 3 1
2 1 3 8 6 7
 2
1 8 9 1 1 0
2 3 4 5 6 7
 2
0 2 9 8 1 7
6 7 4 3 2 5
 3
9 4 6 2 7 0
3 7 1 9 6 4
6 1 0 8 7 2
 3
2 7 4 0 7 1
5 5 4 9 1 4
2 1 7 5 1 7
 3
5 1 2 9 6 4
9 0 6 4 2 8
4 6 2 8 3 7
 3
1 1 1 0 2 3
4 5 6 7 8 9
0 0 0 0 0 0
 1
1 9 8 3 7 8
 3
2 6 3 7 1 0
9 1 2 4 7 6
1 4 8 7 6 2
 1
4 6 9 8 2 7
 2
1 7 6 9 2 5
1 6 7 0 9 2
 3
4 1 0 8 0 2
1 5 3 5 0 7
7 7 2 7 2 2
 1
7 6 5 8 9 0
 3
3 8 3 5 5 5
3 0 1 6 6 3
0 4 3 7 2 4
 1
8 1 9 2 9 7
 2
2 0 5 7 0 8
4 5 1 5 4 9
 3
1 1 1 1 1 1
0 2 3 4 5 6
7 8 9 2 3 4
 3
0 1 1 2 2 3
4 5 6 7 8 9
3 4 5 6 7 1
 1
0 8 7 1 3 2
 2
9 3 3 6 7 2
6 2 9 1 5 9
 1
8 2 7 4 1 0
 2
3 6 8 9 5 0
6 7 0 8 2 3
 1
0 1 2 3 4 5
 3
3 4 5 6 8 9
1 1 1 1 1 1
1 2 4 5 7 0
 2
2 3 5 1 9 6
1 6 8 7 3 9
 2
0 9 5 7 6 2
8 6 2 7 1 4
 2
4 3 8 6 0 1
4 7 1 8 9 0
 1
6 2 8 4 5 1
 1
4 0 9 6 3 1
 2
6 0 1 7 2 9
1 3 4 6 7 0
 3
5 0 7 6 2 1
2 7 4 6 1 9
0 2 6 1 7 5
 3
0 1 1 2 2 3
4 5 6 7 8 9
3 4 5 6 7 8
 3
0 1 2 3 4 5
0 1 2 3 4 5
0 1 2 3 4 5
 2
2 4 0 3 7 6
3 2 8 7 1 5
 1
7 3 6 9 8 1
 3
1 1 2 3 4 5
6 7 8 9 0 2
3 4 5 6 7 8
 3
9 4 3 0 2 6
7 0 5 3 3 9
1 0 7 4 6 7
 1
3 7 7 6 4 2
 3
2 5 7 4 2 7
1 5 5 9 0 3
8 2 0 1 5 1
 2
1 7 8 6 0 9
3 2 1 7 4 9
 2
0 8 6 2 1 3
5 2 7 1 0 9
 2
5 3 2 9 8 2
0 7 4 8 1 8
 3
3 8 5 1 5 5
1 5 7 2 6 9
4 3 4 8 8 9
 2
5 1 2 3 0 8
3 6 7 4 9 2
 2
0 1 2 3 4 5
6 7 8 9 1 2
 1
5 3 8 0 2 6
 1
0 7 6 3 2 4
 2
8 0 6 5 1 4
7 1 0 8 3 4
 2
7 8 6 1 4 5
8 6 4 3 2 5
 2
0 1 2 3 4 5
6 6 6 7 8 9
 3
9 3 1 8 4 6
6 9 1 2 0 7
8 9 1 5 0 3
 3
0 6 2 9 5 4
3 8 0 1 6 9
6 9 0 1 5 2
 3
0 1 2 2 4 5
6 7 8 9 0 1
3 3 4 5 6 7
 1
1 4 5 7 0 5
 2
8 6 4 1 2 0
7 8 5 3 2 1
 3
5 6 2 9 3 5
5 4 1 5 9 8
4 4 2 0 3 5
 1
9 8 1 6 5 7
 3
7 2 1 3 6 9
0 3 8 4 7 6
1 4 5 8 7 0
 3
9 4 3 3 9 3
1 0 3 4 5 3
2 9 6 2 4 1
 3
1 2 3 7 8 9
9 8 7 1 2 3
7 9 2 3 1 8
 3
8 1 8 2 7 1
9 1 9 9 4 7
0 0 9 0 4 0
 1
2 5 9 6 7 9
 3
4 6 0 3 9 2
8 6 9 0 7 2
6 9 3 2 5 7
 3
8 6 0 5 4 9
1 8 5 3 9 7
7 4 5 1 6 8
 1
8 6 0 9 4 2
 1
7 9 2 5 0 4
 1
6 0 7 5 4 8
 2
5 8 4 7 1 2
0 8 6 2 4 9
 1
5 2 2 5 6 7
 2
6 5 2 7 1 3
3 7 8 1 0 9
 1
8 3 5 4 2 9
 3
0 1 2 3 4 5
6 7 8 9 1 2
3 4 5 6 7 8
 2
6 6 4 7 9 0
2 1 2 8 6 4
 3
2 3 4 5 6 7
3 4 5 6 7 8
9 1 2 3 4 5
 2
0 1 2 3 4 5
4 5 6 7 8 9
 3
2 7 3 6 4 5
0 2 1 9 4 8
8 6 9 5 4 0
 2
0 1 2 3 4 5
6 7 8 9 6 6
 2
1 7 2 0 4 3
5 2 3 6 1 0
 1
6 2 8 5 1 3
 3
5 4 8 1 6 7
0 9 3 5 8 6
2 4 7 8 1 3
 1
6 3 1 9 4 9
 3
0 1 9 1 0 8
9 9 3 5 6 2
9 3 9 9 7 3
 3
8 1 6 8 6 8
7 0 2 5 8 4
5 2 0 3 1 9
 3
2 0 1 3 4 5
6 7 8 9 1 1
3 4 5 6 6 7
 3
4 4 5 0 6 6
7 1 6 9 5 4
5 0 4 0 3 9
 2
0 1 2 3 4 5
9 8 7 6 5 4
 2
0 2 9 1 8 5
0 7 4 3 2 5
 2
2 3 9 1 6 7
2 5 4 3 0 6
 2
5 7 4 2 1 9
2 2 7 1 1 8
 1
3 9 1 7 4 5
 3
7 7 2 5 3 2
3 0 0 6 4 4
1 2 1 1 9 1
 1
7 9 5 0 4 6
 3
7 1 3 0 2 4
2 4 3 0 9 5
1 9 8 0 6 5
 1
4 3 8 9 2 3

3
 9
 9
 4
 2
 10
 10
 1
 4
 0
 2
 5
 0
 8
 2
 2
 10
 19
 3
 3
 2
 0
 5
 19
 3
 2
 1
 2
 1
 4
 2
 9
 5
 8
 1
 10
 7
 0
 5
 4
 3
 5
 9
 9
 29
 0
 0
 1
 8
 9
 21
 6
 21
 1
 8
 6
 1
 21
 6
 3
 2
 0
 0
 1
 0
 0
 0
 2
 0
 3
 0
 98
 2
 9
 9
 10
 9
 7
 3
 21
 1
 3
 32
 19
 1
 9
 5
 7
 2
 1
 7
 0
 65
 0

import java.util.*;
import java.io.*;
import java.math.*;
public final class Solution 
{
	static ArrayList<ArrayList<Integer>> adj = new ArrayList<>(); //adjacency list of graph
	static boolean[] visited; //array visited of nodes of graph
    public static void main(String[] args)
    {
   	 Reader input = new Reader();
     PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));
     int n = input.nextInt();
     HashSet<Integer>[] set = new HashSet[n];
     for(int i = 0 ; i < n ; i++)
     {
    	 set[i] = new HashSet<Integer>();
    	 for(int j = 0 ; j < 6 ; j++)
    		 set[i].add(input.nextInt());
     }
     int max = 0;
     for(int i = 1 ; i < 999 ; i++)
     {
    	 boolean found = false;
    	 if(i <= 9) //one digit
    	 {
    		 for(int j = 0 ; j < n ; j++)
    		 {
    			 if(set[j].contains(i))
    			 {
    				 max = i;
    				 found = true;
    				 break;
    			 }
    		 }
    	 }
    	 else if(i > 9 && i < 100) //two
    	 {
    		 int first = i % 10;
    		 int second = i / 10;
    		 for(int j = 0 ; j < n ; j++)
    		 {
    			 if(set[j].contains(first))
    			 {
    				 for(int k = 0 ; k < n ; k++)
    				 {
    					 if(k == j)
    						 continue;
    					 if(set[k].contains(second))
    					 {
    						 found = true;
    						 max = i;
    						 break;
    					 }
    				 }
					 if(found)
						 break;
    			 }
    		 }
    	 }
    	 else //three
    	 {
    		 int first = i % 10;
    		 int second = (i % 100) / 10;
    		 int third = i / 100;
    		 for(int j = 0 ; j < n ; j++)
    		 {
    			 if(set[j].contains(first))
    			 {
    				 for(int k = 0 ; k < n ; k++)
    				 {
    					 if(k == j)
    						 continue;
    					 if(set[k].contains(second))
    					 {
    						 for(int f = 0 ; f < n ; f++)
    						 {
    							 if(f == k || f==j)
    								 continue;
    							 if(set[j].contains(third))
    							 {
    	    						 found = true;
    	    						 max = i;
    	    						 break;
    							 }
    						 }
    					 }
    				 }
					 if(found)
						 break;
    			 }
    		 }
    	 }
    	 if(!found)
    		 break;
     }
     out.println(max);
     out.close();	 
    }  
	public static void bfs(int start) 
	{		
		ArrayList<Integer> queue = new ArrayList<>();
		queue.add(start);
		while(queue.size() != 0)
		{
			int node = queue.get(0);
			queue.remove(0);
			if(visited[node])
				continue;
			visited[node] = true;
			/*do something here with variable node if needed*/
			for(int i = 0 ; i < adj.get(node).size(); i++)
				queue.add(adj.get(node).get(i));
		}
	}

	public static int stronglyConnectedComponents() 
	{
		int count = 0;
		for(int i = 0 ; i < adj.size(); i++)
		{
			if(!visited[i])				
			{
				count++;
				dfs(i);
			}
		}
		return count;
	}
	public static void dfs(int start) 
	{
		/*do something here with the node(start) if needed*/
		visited[start] = true;
		for(int i = 0 ; i < adj.get(start).size(); i++)
		{
			if(visited[adj.get(start).get(i)])
				continue;			
			dfs(adj.get(start).get(i));
		}
	}
    public static int z(int n)
    {
    	/*finds the number of trailing zeros in factorial */
    	int count = 0;
    	for(int i = 5 ; i <= n ; i *= 5)
    	{
    		count += n / i;
    	}
    	return count;
    }
    public static int gcd(int a , int b)
    {
    	if(b == 0)
    		return a;
    	return gcd(b , a %b);
    }
    public static class UnionFind
    {
    	/* this class uses zeroIndexing and gives the result back in zero indexing*/
    	int[] parent;
    	int[] size;
    	int maxSize = 0;
    	public UnionFind(int n)
    	{
    		size = new int[n];
    		parent = new int[n];
    		for(int i = 0 ; i < n ; i++)
    		{
    			parent[i] = i;
    			size[i] = 1;
    		}
    		maxSize = 1;
    	}
    	public int find(int pos)
    	{
    		if(parent[pos] == pos)
    			return pos;
    		return parent[pos] = find(parent[pos]);
    	}
    	public void unify(int x , int y)
    	{
    		int xParent = find(x);
    		int yParent = find(y);
    		if(xParent == yParent)
    			return;
    		else if(size[xParent] > size[yParent]) 
    		{
    			size[xParent] += size[yParent];
    			if(size[xParent] > maxSize)
    				maxSize = size[xParent];
    			parent[yParent] = xParent;
    		}
    		else
    		{
    			size[yParent] += size[xParent];
    			if(size[yParent] > maxSize)
    				maxSize = size[yParent];
    			parent[xParent] = yParent;
    		}
    	}
    	public int maxSize()
    	{
    		return maxSize;
    	}
    	public int connectedComponents()
    	{
    		int count = 0;
    		for(int i = 0 ; i < parent.length ; i++)
    		{
    			if(i == parent[i])
    				count++;
    		}
    		return count;
    	}
    }
    public static class Pair implements Comparable<Pair>
    {
    	int a ,  b;
    	public Pair(int a , int b)
    	{
    		this.a = a;
    		this.b = b;
    	}
		@Override
		public int compareTo(Pair t) {
			// TODO Auto-generated method stub
    		if(t.a == this.a)
    		{
    			if(this.b < t.b)
    				return -1;
    			else if(this.b > t.b)
    				return 1;
    			else
    				return 0;
    		}
    		else if(this.a < t.a)
    			return -1;
    		else
    			return 1;
		}
    }
    public static class Reader
    {
    	BufferedReader br;
    	StringTokenizer st;
    	public Reader()
    	{
    		br = new BufferedReader(new InputStreamReader(System.in));    		
    	}
    	public String next()
    	{
    		try
    		{
        		if(st == null || !st.hasMoreTokens())
        			st = new StringTokenizer(br.readLine());
    		}
    		catch(IOException ex)
    		{
    			ex.printStackTrace();
    			System.exit(1);
    		}    		
    		return st.nextToken();
    	}
    	public int nextInt()
    	{
    		return Integer.parseInt(next());
    	}
    	public double nextDouble()
    	{
    		return Double.parseDouble(next());
    	}
    	public long nextLong()
    	{
    		return Long.parseLong(next());
    	}
    	public String nextLine()
    	{
    		try
    		{
    			return br.readLine();
    		}
    		catch(IOException ex)
    		{
    			ex.printStackTrace();
    			System.exit(1);
    		}
    		return "";
    	}
    }
}