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.*;

public class q2 {
    public static MyScanner in = new MyScanner();
    public static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out), true);
    public static MyViewer view = new MyViewer();
    public static BufferedWriter log = new BufferedWriter(new OutputStreamWriter(System.out));
    public static Random rand = new Random(System.currentTimeMillis());

    public static class Pair<A, B> {
        private final A first;
        private final B second;

        public Pair(A first, B second) {
            super();
            this.first = first;
            this.second = second;
        }

        public int hashCode() {
            int hashFirst = first != null ? first.hashCode() : 0;
            int hashSecond = second != null ? second.hashCode() : 0;

            return (hashFirst + hashSecond) * hashSecond + hashFirst;
        }

        public boolean equals(Object other) {
            if (other instanceof Pair) {
                Pair otherPair = (Pair) other;
                return
                        ((this.first == otherPair.first ||
                                (this.first != null && otherPair.first != null &&
                                        this.first.equals(otherPair.first))) &&
                                (this.second == otherPair.second ||
                                        (this.second != null && otherPair.second != null &&
                                                this.second.equals(otherPair.second))));
            }

            return false;
        }

        public String toString() {
            return "(" + first + ", " + second + ")";
        }

        public A getFirst() {
            return first;
        }

        public B getSecond() {
            return second;
        }
    }

    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
        private boolean randomInput = false;
        private Random rand;

        void randomInput(boolean r) {
            randomInput = r;
            rand = new Random(System.currentTimeMillis());
            //rand = new Random(42);
        }

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

        public MyScanner(InputStream is) {
            br = new BufferedReader(new InputStreamReader(is));
        }

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

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

        int nextInt(int val) {
            return randomInput ? val : Integer.parseInt(next());
        }

        int nextInt(int low, int high) {
            if (randomInput) {
                return rand.nextInt(high - low + 1) + low;
            } else {
                return Integer.parseInt(next());
            }
        }

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

        long nextLong(long val) {
            return randomInput ? val : Long.parseLong(next());
        }

        long nextLong(long low, long high) {
            if (randomInput) {
                return low + ((long) (rand.nextDouble() * (high - low + 1)));
            } else {
                return Long.parseLong(next());
            }
        }

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

        int[] arrayInt(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

        int[] arrayInt(int n, int low, int high) {
            int[] a = new int[n];
            if (randomInput) {
                for (int i = 0; i < n; i++) {
                    a[i] = rand.nextInt(high - low + 1) + low;
                }
            } else {
                for (int i = 0; i < n; i++) {
                    a[i] = nextInt();
                }
            }
            return a;
        }

        ArrayList<Integer> list(int n) {
            ArrayList<Integer> a = new ArrayList<Integer>(n);
            for (int i = 0; i < n; i++) {
                a.add(nextInt());
            }
            return a;
        }

        ArrayList<Integer> list(int n, int low, int high) {
            ArrayList<Integer> a = new ArrayList<Integer>(n);
            if (randomInput) {
                for (int i = 0; i < n; i++) {
                    a.add(rand.nextInt(high - low + 1) + low);
                }
            } else {
                for (int i = 0; i < n; i++) {
                    a.add(nextInt());
                }
            }
            return a;
        }

        long[] arrayLong(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextLong();
            }
            return a;
        }

        long[] arrayLong(int n, long low, long high) {
            long[] a = new long[n];
            if (randomInput) {
                for (int i = 0; i < n; i++) {
                    double r = rand.nextDouble();
                    a[i] = (long) (r * (double) (high - low + 1)) + low;
                    if (a[i] == 0) {
                        out.println("Ouch : " + r);
                    }
                }
            } else {
                for (int i = 0; i < n; i++) {
                    a[i] = nextLong();
                }
            }
            return a;
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        void close() {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        ArrayList<ArrayList<Integer>> randomTree(int n) {
            ArrayList<ArrayList<Integer>> edges = new ArrayList<>();
            for (int i = 0; i < n; i++) {
                edges.add(new ArrayList<>());
            }

            for (int i = 1; i < n; i++) {
                int par = rand.nextInt(i);
                edges.get(par).add(i);
            }
            return edges;
        }
    }

    static class MyViewer {
        static boolean print = true;

        public void on() {
            print = true;
        }

        public void off() {
            print = false;
        }

        public <T extends List> void list(T a) {
            if (!print) return;
            out.print("List: [" + a.get(0));
            for (int i = 1; i < a.size(); i++) {
                out.print(", " + a.get(i));
            }
            out.println("] Len: " + a.size());
        }

        public <T> void array(T[] a) {
            if (!print) return;
            out.print("Array: [" + a[0]);
            for (int i = 1; i < a.length; i++) {
                out.print(", " + a[i]);
            }
            out.println("] Len: " + a.length);
        }

        public void array(boolean[] a) {
            if (!print) return;
            out.print("boolean[] Len: " + a.length + " [");
            for (boolean x : a) {
                out.print(x + ", ");
            }
            out.println("\b\b]");
        }

        public void array(int[] a) {
            if (!print) return;
            out.print("int[] Len: " + a.length + " [");
            for (int x : a) {
                out.print(x + ", ");
            }
            out.println("\b\b]");
        }

        public void array(long[] a) {
            if (!print) return;
            out.print("long Array: [");
            for (long x : a) {
                out.print(x + ", ");
            }
            out.println("\b\b] Len: " + a.length);
        }

        public void matrix(int[][] a, int cutoff) {
            if (cutoff == 0)
                cutoff = Integer.MAX_VALUE;
            for (int i = 0; i < a.length; i++) {
                if (i < cutoff) {
                    printMatrixRow(a[i], cutoff);
                } else {
                    out.println("     ...");
                    printMatrixRow(a[a.length - 1], cutoff);
                    break;
                }
            }
        }

        public void matrix(long[][] a, long cutoff) {
            if (cutoff == 0)
                cutoff = Long.MAX_VALUE;
            for (int i = 0; i < a.length; i++) {
                if (i < cutoff) {
                    printMatrixRow(a[i], cutoff);
                } else {
                    out.println("     ...");
                    printMatrixRow(a[a.length - 1], cutoff);
                    break;
                }
            }
        }

        public void matrix(boolean[][] a, int cutoff) {
            if (cutoff == 0)
                cutoff = Integer.MAX_VALUE;
            for (int i = 0; i < a.length; i++) {
                if (i < cutoff) {
                    printMatrixRow(a[i], cutoff);
                } else {
                    out.println("     ...");
                    printMatrixRow(a[a.length - 1], cutoff);
                    break;
                }
            }
        }

        private void printMatrixRow(int[] a, int cutoff) {
            for (int j = 0; j < a.length; j++) {
                if (j < cutoff) {
                    out.printf("%6d  ", a[j]);
                } else {
                    out.printf(" ... %6d", a[a.length - 1]);
                    break;
                }
            }
            out.println();
        }

        private void printMatrixRow(long[] a, long cutoff) {
            for (int j = 0; j < a.length; j++) {
                if (j < cutoff) {
                    out.printf("%6d  ", a[j]);
                } else {
                    out.printf(" ... %6d", a[a.length - 1]);
                    break;
                }
            }
            out.println();
        }

        private void printMatrixRow(boolean[] a, int cutoff) {
            for (int j = 0; j < a.length; j++) {
                if (j < cutoff) {
                    out.print(a[j] ? "T " : "F ");
                } else {
                    out.print(" ... " + (a[a.length - 1] ? "T" : "F"));
                    break;
                }
            }
            out.println();
        }

    }

    public static void main(String[] args) throws IOException {

        int n = in.nextInt();
        ArrayList<HashSet<Integer>> a = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            a.add(new HashSet<Integer>());
            for (int j = 0; j < 6; j++) {
                a.get(i).add(in.nextInt());
            }
        }

        if (n == 1) {
            nextInt2:
            for (int i = 1; i < 10; i++) {
                if (a.get(0).contains(i)) {
                    continue nextInt2;
                }
                out.println(i - 1);
                System.exit(0);
            }
        } else if (n == 3) {
            int[][] perm = {{0, 1, 2}, {0, 2, 1}, {1, 0, 2}, {1, 2, 0}, {2, 0, 1}, {2, 1, 0}};
            nextInt:
            for (int i = 1; i < 1000; i++) {
                for (int[] p : perm) {
                    if (i < 10) {
                        if (a.get(p[0]).contains(i))
                            continue nextInt;
                    } else if (i < 100) {
                        if (a.get(p[0]).contains(i % 10) && a.get(p[1]).contains(i / 10))
                            continue nextInt;
                    } else if (i < 1000) {
                        if (a.get(p[0]).contains(i % 10) && a.get(p[1]).contains((i / 10) % 10) && a.get(p[2]).contains(i / 100))
                            continue nextInt;
                    }
                }
                out.println(i - 1);
                System.exit(0);
            }
        } else if (n == 2) {
            int[][] perm = {{0, 1}, {1, 0}};
            nextInt1:
            for (int i = 1; i < 100; i++) {
                for (int[] p : perm) {
                    if (i < 10) {
                        if (a.get(p[0]).contains(i))
                            continue nextInt1;
                    } else if (i < 100) {
                        if (a.get(p[0]).contains(i % 10) && a.get(p[1]).contains(i / 10))
                            continue nextInt1;
                    }
                    out.println(i - 1);
                    System.exit(0);
                }
            }
        }
        out.println(0);
        log.flush();
        in.close();
    }
}