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.ArrayList;
import java.util.HashMap;
import java.util.Scanner;

public class B_444_2 {

	static int mxNum(HashMap<Integer, Boolean> m) {
		int res = 0;
		for (int i = 1; i <= m.size(); i++) {
			if (!m.containsKey(i))
				break;
			res = i;
		}
		return res;
	}

	static int mxNum(HashMap<Integer, Boolean> m1, HashMap<Integer, Boolean> m2) {
		int res = 0;
		HashMap<Integer, Boolean> all = new HashMap<>();
		all.putAll(m1);
		all.putAll(m2);
		res = mxNum(all);
		if (res < 9)
			return res;
		for (int i = 10; i <= 99; i++) {
			int d1 = i / 10;
			int d2 = i % 10;

			if (!(m1.containsKey(d1) && m2.containsKey(d2)) && !(m1.containsKey(d2) && m2.containsKey(d1))) {
				
				break;
			}
			res = i;
		}
		return res;
	}

	static int mxNum(ArrayList<HashMap<Integer, Boolean>> cubes) {
		int res = 0;
		for(int n = 1; n < 10; n++) {
			for(int i = 0; i < 3; i++) {
				if(cubes.get(i).containsKey(n)) {
					res = n;
					break;
				}
			}
			if(res != n) break;
		}
		if(res < 9) return res;
		for(int n = 10; n < 100; n++) {
			String s = String.valueOf(n);
			int d1 = s.charAt(0) - '0';
			int d2 = s.charAt(1) - '0';
			boolean f = false;
			for(int i = 0; i < 3; i++) {
				f = false;
				if(cubes.get(i).containsKey(d1)) {
					for(int j = 0; j < 3; j++) {
						if(i == j) continue;
						if(cubes.get(j).containsKey(d2)) {
							res = n;
							f = true;
							break;
						}
					}
				}
				if(f) break;
			}
			if(res != n) break;
		}
		if(res < 99) return res;
		for (int n = 1; n <= 999; n++) {
			String s = String.valueOf(n);
			int d1 = s.charAt(0) - '0';
			int d2 = s.charAt(1) - '0';
			int d3 = s.charAt(2) - '0';
			boolean f = false;
			for (int i = 0; i < 3; i++) {
				f = false;
				if (cubes.get(i).containsKey(d1)) {
					for (int j = 0; j < 3; j++) {
						if(i == j) continue;
						if (cubes.get(j).containsKey(d2)) {
							for (int k = 0; k < 3; k++) {
								if(k == i || k == j) continue;
								if (cubes.get(k).containsKey(d3)) {
									res = n;
									f = true;
									break;
								}
							}
						}
						if(f) break;
					}
				}
				if(f)break;
			}
			if (res != n)
				break;
		}
		return res;
	}

	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		int n = scn.nextInt();
		int res = 0;
		ArrayList<HashMap<Integer, Boolean>> cubes = new ArrayList<>();
		cubes.add(new HashMap<>());
		for (int i = 0; i < 6; i++) {
			int num = scn.nextInt();
			cubes.get(0).put(num, true);
		}
		if (n == 1) {
			res = mxNum(cubes.get(0));
		} else if (n == 2) {
			cubes.add(new HashMap<>());
			for (int i = 0; i < 6; i++) {
				int num = scn.nextInt();
				cubes.get(1).put(num, true);
			}

			res = Math.max(mxNum(cubes.get(0)), mxNum(cubes.get(1)));
			res = Math.max(res, mxNum(cubes.get(0), cubes.get(1)));

		} else if (n == 3) {
			cubes.add(new HashMap<>());
			for (int i = 0; i < 6; i++) {
				int num = scn.nextInt();
				cubes.get(1).put(num, true);
			}
			cubes.add(new HashMap<>());
			for (int i = 0; i < 6; i++) {
				int num = scn.nextInt();
				cubes.get(2).put(num, true);
			}

			res = Math.max(mxNum(cubes.get(0)), mxNum(cubes.get(1)));
			res = Math.max(res, mxNum(cubes.get(0), cubes.get(1)));
			res = Math.max(res, mxNum(cubes));

		}
		System.out.println(res);

	}

}