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.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.Vector;


public class solve {
	@SuppressWarnings("unchecked")
	public static void main(String[] args) throws IOException{
		
		FastScanner sc = new FastScanner();
	    PrintWriter out = new PrintWriter(System.out);
	    int n =sc.nextInt();
	    int a[][]=new int[n][6];
	    for(int i=0;i<n;i++)
	    	for(int j=0;j<6;j++)
	    		a[i][j]=sc.nextInt();
	    System.out.println(n2(a));
	   
	    
	if(n==1){
		System.out.println(n1(a));
		
		
	}
	if(n==2){
		System.out.println(Math.max(n1(a),n2(a)));
		
	}
	if(n==3){
		System.out.println(Math.max(n3(a),Math.max(n1(a),n2(a))));
		
	}
	
	    
	}



	
	 

	
	
	public static boolean contains(int[]a , int x){
		for(int i=0;i<a.length;i++)
			if(a[i]==x)return true;
		return false;
	}

	static int n1(int a[][]){
		int ans=0;
		int max=-1;
		for(int i1=1;i1<=9;i1++){
			boolean valid=false;
		for(int i=0;i<a.length;i++){
			
		    	
		    		if(contains(a[i],i1))
		    			valid=true;
		    			
		    	}
		if(!valid)return i1-1;
			
	}
		return 9;
	}
	static int n2(int a[][]){
		int ans =0; 
		int max=-1;
		for(int i=10;i<=99;i++){
			int x =i%10;
			int y= i/10;
			boolean valid=false;
			for(int k1=0;k1<a.length;k1++)
				for(int k2=0;k2<a.length ;k2++){
					if(k1!=k2 &&contains(a[k1], x) && contains(a[k2], y)  ){
						valid=true;
						ans=i;
					}
				}
			if(!valid) return ans=i-1;
		}
		return 99;
		
	}
	static int n3(int a[][]){
		int ans =0; 
		int max=-1;
		for(int i=100;i<=999;i++){
			int x =i%10;
			int y= i/10;
			int z =i/100;
			boolean valid=false;
			for(int k1=0;k1<a.length;k1++)
				for(int z1=0;z1<a.length;z1++)
				for(int k2=0;k2<a.length;k2++){
					Set<Integer> set = new HashSet<Integer>();
					set.add(k1);
					set.add(k2);
					set.add(z1);

					if(set.size()==3 && contains(a[k1], x) && contains(a[k2], y) && contains(a[z1],z)  ){
						valid=true;
						ans=i;
					}
				}
			if(!valid) return ans=i-1;
		}
		return 999;
		
	}
	
	

	
	





}
	



	    	
class pair implements Comparable{
	int x ,y,z;
	pair(int x,int y,int z)
	{
		this.x=x;
		this.y=y;
		this.z=z;
	}
	@Override
	public int compareTo(Object arg0) {
		
		pair u =((pair)arg0);
		
		return -this.z+u.z;
	}
}
 	


	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
	    
  

	  
	   
	    	
	    	
	 
	    
	    
	    		
	  	
	    	
	    	
	 
	 





















class FastScanner {




    BufferedReader br;
    StringTokenizer st;

    public FastScanner() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    public FastScanner(String s) {
        try {
            br = new BufferedReader(new FileReader(s));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    String nextToken() {
        while (st == null || !st.hasMoreElements()) {
            try {
            	
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    int nextInt() {
        return Integer.parseInt(nextToken());
    }

    long nextLong() {
        return Long.parseLong(nextToken());
    }

    double nextDouble() {
        return Double.parseDouble(nextToken());
    }
 

}
