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.*;
import java.util.*;

/**
 * Created by Artem on 15.09.2017.
 */
public class Task {
    private String NAME = "";
    private String ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE");
    private BufferedReader in;
    private PrintWriter out;
    private StringTokenizer tok;

    public void init() throws FileNotFoundException {
        if (ONLINE_JUDGE != null) {
            if (NAME == "") {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            } else {
                in = new BufferedReader(new FileReader(NAME + ".in"));
                out = new PrintWriter(NAME + ".out");
            }
        } else {
            in = new BufferedReader(new FileReader("input.txt"));
            out = new PrintWriter("output.txt");
        }
        tok = new StringTokenizer("");
    }

    private String readLine() throws IOException {
        return in.readLine();
    }

    private String readString() throws IOException {
        if (!tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }

    public int readInt() throws IOException {
        return Integer.parseInt(readString());
    }

    public long readLong() throws IOException {
        return Long.parseLong(readString());
    }

    public double readDouble() throws IOException {
        return Double.parseDouble(readString());
    }

    public int[] readIntArray(int n) throws IOException {
        int[] array = new int[n];
        for (int i = 0; i < array.length; i++) {
            array[i] = readInt();
        }
        return array;
    }

    private long timeBegin, timeEnd;

    public static void main(String[] args) throws IOException {
        new Task().run();
    }

    class Pair<X, Y> implements Comparable<Pair<X, Y>> {
        X x;
        Y y;

        public Pair(X x, Y y) {
            this.x = x;
            this.y = y;
        }

        X getX() {
            return x;
        }

        Y getY() {
            return y;
        }

        @Override
        public int compareTo(Pair<X, Y> o) {
            if (x instanceof Comparable && y instanceof Comparable) {
                int result = ((Comparable) x).compareTo(o.x);
                if (result == 0) {
                    return ((Comparable) y).compareTo(o.y);
                } else {
                    return -result;
                }
            }
            return 0;
        }

    }

    public void run() throws IOException {
        timeBegin = System.currentTimeMillis();
        init();
        solve();
        if (ONLINE_JUDGE == null) {
            //time();
        }

        out.close();
    }

    public void time() {
        timeEnd = System.currentTimeMillis();
        out.println();
        out.println("Time =" + (timeEnd - timeBegin));
    }

    //YOUR SOLVE////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    public void solve() throws IOException {
        int n = readInt();
        TreeSet<Integer> nums = new TreeSet<>();
        int[] a1 = readIntArray(6);
        for (int i = 0; i < 6; i++) {
            if (a1[i] != 0) {
                nums.add(a1[i]);
            }
        }
        int[] a2 = new int[6];
        int[] a3 = new int[6];
        if (n >= 2) {
            a2 = readIntArray(6);
            for (int i = 0; i < 6; i++) {
                if (a2[i] != 0) {
                    nums.add(a2[i]);
                }
            }
            for (int i = 0; i < 6; i++) {
                for (int j = 0; j < 6; j++) {
                    if (a1[i] != 0) {
                        nums.add(a1[i] * 10 + a2[j]);
                    }
                    if (a2[j] != 0) {
                        nums.add(a2[j] * 10 + a1[i]);
                    }
                }
            }
        }
        if (n >= 3) {
            a3 = readIntArray(6);
            for (int i = 0; i < 6; i++) {
                if (a3[i] != 0) {
                    nums.add(a3[i]);
                }
            }
            for (int i = 0; i < 6; i++) {
                for (int j = 0; j < 6; j++) {
                    for (int k = 0; k < 6; k++) {
                        if (a1[i] != 0) {
                            nums.add(a1[i] * 100 + a2[j] * 10 + a3[k]);
                            nums.add(a1[i] * 100 + a3[k] * 10 + a2[j]);
                            nums.add(a1[i] * 10 + a3[k]);
                        }
                        if (a2[j] != 0) {
                            nums.add(a2[j] * 100 + a1[i] * 10 + a3[k]);
                            nums.add(a2[j] * 100 + a3[k] * 10 + a1[i]);
                            nums.add(a2[j] * 10 + a3[k]);
                        }
                        if (a3[k] != 0) {
                            nums.add(a3[k] * 100 + a2[j] * 10 + a1[i]);
                            nums.add(a3[k] * 100 + a1[i] * 10 + a2[j]);
                            nums.add(a3[k] * 10 + a2[j]);
                            nums.add(a3[k] * 10 + a1[i]);
                        }
                    }
                }
            }
        }
        ArrayList<Integer> list = new ArrayList<>();
        for (Integer num : nums) {
            list.add(num);
        }
        int current = 0;
        int ans = 0;
        Collections.sort(list);
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i) - current == 1) {
                ans = list.get(i);
                current = list.get(i);
            }
        }
        out.print(ans);
    }


}