import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class FBJSolve {

  public static List<String> words = new ArrayList<String>();
  public static char[][] grid;
  public static boolean[][] visited;
  public static int size;

  public static void main(String[] args) throws Exception {
    Scanner s = new Scanner(new File("ospd3.txt"));

    while (s.hasNext()) {
      String word = s.next();
      if (word.length() < 3) continue;
      words.add(word);
    }

    size = Integer.parseInt(args[0]);
    grid = new char[size][size];
    visited = new boolean[size][size];

    Scanner ins = new Scanner(System.in);
    for(int i=0;i<size;i++) {
      String line = ins.nextLine();
      for(int j=0;j<size;j++)
        grid[i][j] = line.charAt(j);
    }

    // for each word attempt to match
    nextWord:
    for (String word : words) {
      for(int i=0;i<size;i++)
        for(int j=0;j<size;j++) {
          if( canMatch(word, 0, i,j) ) {
            System.out.println(word);
            continue nextWord;
          }
        }
    }
  }

  public static boolean canMatch(String word, int offset, int row, int col) {
    if (offset >= word.length())
      return true;
    if (row < 0 || row >= size || col < 0 || col >= size)
      return false;
    if (visited[row][col] || grid[row][col] != word.charAt(offset))
      return false;

    boolean matched = false;
    visited[row][col] = true;
    matched |= canMatch(word, offset+1, row-1, col-1);
    matched |= canMatch(word, offset+1, row-1, col+1);
    matched |= canMatch(word, offset+1, row+1, col-1);
    matched |= canMatch(word, offset+1, row+1, col+1);
    matched |= canMatch(word, offset+1, row-1, col);
    matched |= canMatch(word, offset+1, row, col-1);
    matched |= canMatch(word, offset+1, row+1, col);
    matched |= canMatch(word, offset+1, row, col+1);
    visited[row][col] = false;
    return matched;
  }
}