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.HashSet;
import java.util.Set;

public class Main {
	private static Object unexpected = null;
	private static final int mod = (int) 1E9 + 7;
	private static final int ibufsize = (1 << 15), obufsize = (1 << 15);
	private static int iNextByte, iNextIndex, iReadByteCount, oNextIndex;
	private static final byte ibuf[] = new byte[ibufsize], obuf[] = new byte[obufsize];
	private static InputStream is = System.in;
	private static OutputStream os = System.out;

	private Main() throws Exception {
		if (inFromFile) is = new FileInputStream(new File("").getAbsolutePath() + "/src/testdata/in.txt");
		if (outToFile) os = new FileOutputStream(new File("").getAbsolutePath() + "/src/testdata/out.txt");
		nextByte();
		solve();
		is.close();
		flushOutBuf();
	}

	public static void main(String[] args) {
		try {
			new Main();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	private boolean isDigit(int cp) {
		return '0' <= cp && cp <= '9';
	}

	private boolean isLowercase(int cp) {
		return 'a' <= cp && cp <= 'z';
	}

	private boolean isUppercase(int cp) {
		return 'A' <= cp && cp <= 'Z';
	}

	private boolean isAlphabet(int cp) {
		return ('a' <= cp && cp <= 'z') || ('A' <= cp && cp <= 'Z');
	}

	private boolean isAlphanumberic(char ch) {
		return (ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'z') || (ch >= 'A' || ch <= 'Z');
	}

	private boolean isWhitespace(int cp) {
		return cp == ' ' || cp == '\r' || cp == '\n' || cp == '\t';
	}

	private boolean isWordSeparator(int cp) {
		return cp == ' ' || cp == '\r' || cp == '\n' || cp == '\t';
	}

	private boolean isLineSeparator(int cp) {
		return cp == '\n' || cp == '\r';
	}

	private boolean isUnexpected() {
		return unexpected != null;
	}

	private Object setUnexpected(Object value) {
		return (unexpected = value);
	}

	private boolean isNegative() throws IOException {
		boolean minus = false;
		while (iNextByte == '+' || iNextByte == '-') {
			if (iNextByte == '-') minus = !minus;
			nextByte();
		}
		return minus;
	}

	private int nextByte() throws IOException {
		if (iNextIndex >= iReadByteCount) {
			iReadByteCount = is.read(ibuf, 0, ibufsize);
			if (iReadByteCount == -1) return (iNextByte = -1);
			iNextIndex = 0;
		}
		return (iNextByte = ibuf[iNextIndex++]);
	}

	private char nc() throws IOException {
		return (char) nextByte();
	}

	private char[] nc(int n) throws IOException {
		char a[] = new char[n];
		for (int i = 0; i < n; ++i) a[i] = nc();
		return a;
	}

	private char[][] nc(int r, int c) throws IOException {
		char a[][] = new char[r][c];
		for (int i = 0; i < r; ++i) a[i] = nc(c);
		return a;
	}

	private int ni() throws IOException {
		while (isWhitespace(iNextByte)) nextByte();
		int res = 0;
		boolean minus = isNegative();
		if (!isDigit(iNextByte)) return (int) setUnexpected(-1);
		do {res = (res << 1) + (res << 3) + iNextByte - '0';} while (isDigit(nextByte()));
		return minus ? -res : res;
	}

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

	private int[][] ni(int r, int c) throws IOException {
		int a[][] = new int[r][c];
		for (int i = 0; i < r; ++i) a[i] = ni(c);
		return a;
	}

	private long nl() throws IOException {
		while (isWhitespace(iNextByte)) nextByte();
		long res = 0;
		boolean minus = isNegative();
		if (!isDigit(iNextByte)) return (long) setUnexpected(-1);
		do {res = (res << 1) + (res << 3) + iNextByte - '0';} while (isDigit(nextByte()));
		return minus ? -res : res;
	}

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

	private long[][] nl(int r, int c) throws IOException {
		long a[][] = new long[r][c];
		for (int i = 0; i < r; ++i) a[i] = nl(c);
		return a;
	}

	private double nd() throws IOException {
		while (isWhitespace(iNextByte)) nextByte();
		boolean minus = isNegative();
		if (!isDigit(iNextByte)) return (double) setUnexpected(-1.0);
		double decimal = 0, floating = 0, div = 1;
		do {decimal = 10 * decimal + (iNextByte - '0');} while (isDigit(nextByte()));
		if (iNextByte == '.') while (isDigit(nextByte())) floating += (iNextByte - '0') / (div *= 10);
		double res = decimal + floating;
		return minus ? -res : res;
	}

	private double[] nd(int n) throws IOException {
		double a[] = new double[n];
		for (int i = 0; i < n; ++i) a[i] = nd();
		return a;
	}

	private double[][] nd(int r, int c) throws IOException {
		double a[][] = new double[r][c];
		for (int i = 0; i < r; ++i) a[i] = nd(c);
		return a;
	}

	private String line() throws IOException {
		while (isWhitespace(iNextByte)) nextByte();
		StringBuilder sb = new StringBuilder();
		while (iNextByte != -1 && !isLineSeparator(iNextByte)) {
			sb.append((char) iNextByte);
			nextByte();
		}
		return sb.toString();
	}

	private String ns() throws IOException {
		while (isWordSeparator(iNextByte)) nextByte();
		StringBuilder sb = new StringBuilder();
		while (iNextByte != -1 && !isWordSeparator(iNextByte)) {
			sb.append((char) iNextByte);
			nextByte();
		}
		return sb.toString();
	}

	private String[] ns(int n) throws IOException {
		String a[] = new String[n];
		for (int i = 0; i < n; ++i) a[i] = ns();
		return a;
	}

	private String[][] ns(int r, int c) throws IOException {
		String a[][] = new String[r][c];
		for (int i = 0; i < r; ++i) a[i] = ns(c);
		return a;
	}

	private void flushOutBuf() {
		if (oNextIndex == 0) return;
		try {
			os.write(obuf, 0, oNextIndex);
			os.flush();
			oNextIndex = 0;
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	private void puts(String format, Object... args) {
		if (args != null) format = String.format(format, args);
		for (int i = 0, n = format.length(); i < n; ++i) {
			obuf[oNextIndex++] = (byte) format.charAt(i);
			if (oNextIndex >= obufsize) flushOutBuf();
		}
	}

	private <T> void print(T ob) {
		puts(ob + "");
	}

	private void print(String format, Object... args) {
		puts(format, args);
	}

	private <T> void println(T ob) {
		puts(ob + "\n");
	}

	private void println(String format, Object... args) {
		puts(format + "\n", args);
	}

	private <T> void debug(T ob) {
		puts("\u001B[31m" + ob + "\u001B[0m");
	}

	private <T> void debug(String format, Object... args) {
		puts("\u001B[31m" + format + "\u001B[0m", args);
	}

	private <T> void debugln(T ob) {
		puts("\u001B[31m" + ob + "\u001B[0m\n");
	}

	private void debugln(String format, Object... args) {
		puts("\u001B[31m" + format + "\u001B[0m\n", args);
	}

	private static final boolean inFromFile = false, outToFile = false;

	private void solve() throws Exception {
		int n = ni(), a[][] = ni(n, 6);
		int v;
		for (v = 1; v < 100; ++v) {
			if (!canBuild(v + "", a)) {
				break;
			}
		}
		println(v == 1 ? 0 : v-1);
	}

	boolean canBuild(String s, int[][] a) {
		Set<Integer> set = new HashSet<>();
		for (int i = 0; i < a.length; ++i) {
			int b[] = a[i];
			for (char ch : s.toCharArray()) {
				if (contains(b, ch)) set.add(i);
			}
		}
		return set.size() >= s.length();
	}

	boolean contains(int[] a, char ch) {
		int value = ch - '0';
		for (int v : a) if (v == value) return true;
		return false;
	}
}
