import java.io.*;
import java.math.*;

public class C_kosak_2
{
	public static void main(String pArgs[]) throws IOException
	{
		BufferedReader	in = new BufferedReader(new InputStreamReader(System.in));
		while (solve(in, System.out))
			;
		in.close();
	}
	
	private static boolean solve(BufferedReader pIn, PrintStream pOut) throws IOException
	{
		String		line;
		int			index, width, height;
		char[][]	matrix;
		
		//	行列のサイズを読む
		line = pIn.readLine();
		index = line.indexOf(' ');
		width = Integer.parseInt(line.substring(0, index));
		height = Integer.parseInt(line.substring(index + 1));
		if (width == 0 && height == 0)
			return false;
		matrix = new char[height][width];
		
		//	行列を読む
		for (int h = 0; h < height; h++) {
			line = pIn.readLine();
			for (int w = 0; w < width; w++)
				matrix[h][w] = line.charAt(w);
		}
		
		//	表を作成
		BigInteger[][]	table = new BigInteger[height + 1][width + 1];
		BigInteger		biggest = null;
		char			chr;
		for (int h = 0; h <= height; h++)
			table[h][0] = BigInteger.ZERO;
		for (int w = 0; w <= width; w++)
			table[0][w] = BigInteger.ZERO;
		for (int h = 1; h <= height; h++) {
			for (int w = 1; w <= width; w++) {
				chr = matrix[h - 1][w - 1];
				if (chr >= '0' && chr <= '9') {
					if (table[h - 1][w].compareTo(table[h][w - 1]) > 0)
						table[h][w] = new BigInteger(table[h - 1][w].toString() + chr);
					else
						table[h][w] = new BigInteger(table[h][w - 1].toString() + chr);
					if (biggest == null || table[h][w].compareTo(biggest) > 0)
						biggest = table[h][w];
				} else
					table[h][w] = BigInteger.ZERO;
			}
		}
		
		pOut.println(biggest == null ? "No secrets..." : biggest.toString());
		
		return true;
	}	//	solve
}	//	class C_kosak_2