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
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8 6 4 1 2 0
7 8 5 3 2 1
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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
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1 2 3 7 8 9
9 8 7 1 2 3
7 9 2 3 1 8
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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
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8 6 0 5 4 9
1 8 5 3 9 7
7 4 5 1 6 8
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8 6 0 9 4 2
 1
7 9 2 5 0 4
 1
6 0 7 5 4 8
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5 8 4 7 1 2
0 8 6 2 4 9
 1
5 2 2 5 6 7
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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
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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
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1 7 2 0 4 3
5 2 3 6 1 0
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6 2 8 5 1 3
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5 4 8 1 6 7
0 9 3 5 8 6
2 4 7 8 1 3
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6 3 1 9 4 9
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0 1 9 1 0 8
9 9 3 5 6 2
9 3 9 9 7 3
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8 1 6 8 6 8
7 0 2 5 8 4
5 2 0 3 1 9
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2 0 1 3 4 5
6 7 8 9 1 1
3 4 5 6 6 7
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4 4 5 0 6 6
7 1 6 9 5 4
5 0 4 0 3 9
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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
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2 3 9 1 6 7
2 5 4 3 0 6
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5 7 4 2 1 9
2 2 7 1 1 8
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3 9 1 7 4 5
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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.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
	static BufferedReader br;
    static StringTokenizer sc;
    static PrintWriter out;

    public static void main(String[] args) throws IOException {
        //br = new BufferedReader(new FileReader("input.in"));
    	br = new BufferedReader(new InputStreamReader(System.in));
        //out = new PrintWriter("output.out");
    	out = new PrintWriter(System.out);
        sc = new StringTokenizer("");
        
        TaskD solver = new TaskD();
        solver.solve();
        
        br.close();
        out.close();
        //System.out.println("Finished");
    }    
    
    static class TaskD {
        public void solve() throws IOException {
        	int n = nxtInt();
        	
        	int[] nums = new int[10];
        	
        	for (int i = 0; i < n * 6; i++) {
        		nums[nxtInt()]++;
        	}
        	
        	int sol = 0;
        	
        	start:
        	for (int i = 1; i < 1000; i++) {
        		int[] newNums = new int[10];
        		for (int j = 0; j < 10; j++)
        			newNums[j] = nums[j];
        		
        		int x = i;
        		
        		while (x > 0) {
        			int xx = x % 10;
        			if (newNums[xx] > 0)
        				newNums[xx]--;
        			else
        				break start;
        			
        			x = x / 10;
        		}
        		
        		sol = i;
        	}
        	
        	out.println(sol);
        }
        
        char[] toBin(int n) {
        	char[] num = new char[10];
        	
        	int index = 0;
        	
        	while (n > 0) {
        		if (n % 2 == 0)
        			num[index++] = '0';
        		else
        			num[index++] = '1';
        		
        		n = n / 2;
        	}
        	
        	for (int i = index; i < 10; i++)
        		num[i] = '0';
        	
        	return num;
        }

        class Trie {
            Node root;

            Trie() {
                root = new Node();
            }

            void add(long x) {

                Node cur = root;
                // int depth = 0;
                while (x > 0) {
                    int ls = (int)(x % 10);
                    x /= 10;
                    cur.cnt[ls]++;
                    if (cur.nodes[ls] == null)
                        cur.nodes[ls] = new Node();
                    cur = cur.nodes[ls];
                }
            }

            void sub(long x) {

                Node cur = root;
                while (x > 0) {
                    int ls = (int)(x % 10);
                    x /= 10;
                    cur.cnt[ls]--;
                    cur = cur.nodes[ls];
                }
            }

            long[] getcnt(long x) {

                int res = 0;
                int prev = 0;
                int depth = 0;
                Node cur = root;

                while (x > 0 && depth < 10) {
                    int ls = (int)(x % 10);
                    x /= 10;
                    res = cur.cnt[9 - ls];
                    if (res != 0) {
                        depth++;
                        prev = res;
                        cur = cur.nodes[9 - ls];
                    } else
                        break;
                }

                return new long[]{depth, prev};
            }

        }

        class Node {
            Node[] nodes;
            int[] cnt;

            Node() {
                nodes = new Node[10];
                cnt = new int[10];
            }

        }

    }

    static String nxtTok() throws IOException {
        while (!sc.hasMoreTokens()) {
            String s = br.readLine();
            
            if (s == null) {
                return null;
            }
            sc = new StringTokenizer(s.trim());
        }
        return sc.nextToken();
    }

    static int nxtInt() throws IOException {
        return Integer.parseInt(nxtTok());
    }

    static long nxtLng() throws IOException {
        return Long.parseLong(nxtTok());
    }

    static double nxtDbl() throws IOException {
        return Double.parseDouble(nxtTok());
    }

    static int[] nxtIntArr(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = nxtInt();
        }
        return a;
    }

    static long[] nxtLngArr(int n) throws IOException {
        long[] a = new long[n];
        for (int i = 0; i < n; i++) {
            a[i] = nxtLng();
        }
        return a;
    }

    static char[] nxtCharArr() throws IOException {
        return nxtTok().toCharArray();
    }
    
    static int getMin(int arr[], int count)
    {
    	int min = arr[0];
    	for (int i = 1; i < count; i++)
    		if (arr[i] < min)
    			min = arr[i];

    	return min;
    }

    static int getMax(int arr[], int count)
    {
    	int max = arr[0];
    	for (int i = 1; i < count; i++)
    		if (arr[i] > max)
    			max = arr[i];

    	return max;
    }

    static void sortAsc(int arr[], int count)
    {
        int temp;

        for (int i = 0; i < count - 1; i++)
        {
            for (int j = i + 1; j < count; j++)
            {
                if (arr[i] > arr[j])
                {
                    temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
        }
    }

    static void sortDesc(int arr[], int count)
    {
        int temp;

        for (int i = 0; i < count - 1; i++)
        {
            for (int j = i + 1; j < count; j++)
            {
                if (arr[i] < arr[j])
                {
                    temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
        }
    }
}