package pack;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import java.util.ArrayList;
import java.util.List;

public class FindWords {
    private List<String> data = null, words = null;
    private StringBuffer dataBufferWE = null, dataBufferNS = null, dataBufferNE = null, dataBufferWN = null, dataBufferAll = null;
    private List<String> positionWE = null, positionNS = null, positionNE = null, positionWN = null, positionAll = null, usedCoordinates = null;
    private int row = -1, column = -1;

    public FindWords() {
        data = new ArrayList<String>();
        words = new ArrayList<String>();
        dataBufferWE = new StringBuffer();
        dataBufferNS = new StringBuffer();
        dataBufferNE = new StringBuffer();
        dataBufferWN = new StringBuffer();
        dataBufferAll = new StringBuffer();
        positionWE = new ArrayList<String>();
        positionNS = new ArrayList<String>();
        positionNE = new ArrayList<String>();
        positionWN = new ArrayList<String>();
        positionAll = new ArrayList<String>();
        usedCoordinates = new ArrayList<String>();
    }

    public static void main(String[] args) {
        FindWords findWords = new FindWords();
        String result = findWords.parseFile(args[0]);
        System.out.println(result);
    }

    public String parseFile(String fileName) {
        try {
            BufferedReader reader = new BufferedReader(new FileReader(new File(fileName)));
            String line = reader.readLine();
            column = line.length();
            int lastIndexWN = 0;
            while (!line.equals("")) {
                row++;
                data.add(line);
                dataBufferWE.append(line + "#");
                int indexNS = row, incrementNS = row + 1;
                int indexNE = 0, incrementNE = 1;
                lastIndexWN += row > column ? column : row;
                int indexWN = lastIndexWN, incrementWN = row >= column ? column : row + 1;
                int position = 0;
                for(char letter : line.toCharArray()) {
                    positionWE.add(row + "::" + position);
                    dataBufferNS.insert(indexNS, letter);
                    positionNS.add(indexNS, row + "::" + position);
                    indexNS += incrementNS;
                    dataBufferNE.insert(indexNE, letter);
                    positionNE.add(indexNE, row + "::" + position);
                    incrementNE = incrementNE < (row + 1) ? incrementNE + 1: incrementNE;
                    indexNE += incrementNE;
                    dataBufferWN.insert(indexWN, letter);
                    positionWN.add(indexWN, row + "::" + position);
                    indexWN += incrementWN;
                    incrementWN -= (column - position) <= (row + 1) ? 1 : 0;
                    position++;
                }
                positionWE.add("#");
                line = reader.readLine();
            }
            row++;
            int indexNS = row;
            while(indexNS < dataBufferNS.length() - 1) {
                dataBufferNS.insert(indexNS, "#");
                positionNS.add(indexNS, "#");
                indexNS += row + 1;
            }
            dataBufferNS.insert(0, "#");
            positionNS.add(0, "#");
            dataBufferNS.append("#");
            positionNS.add("#");
            int loopValue = row < column ? row : column;
            int forwardIndex = 0;
            int reverseIndex = dataBufferNE.length();
            for(int index = 1; index < loopValue; index++) {
                reverseIndex -= index;
                forwardIndex += index;
                dataBufferNE.insert(reverseIndex, "#");
                positionNE.add(reverseIndex, "#");
                dataBufferNE.insert(forwardIndex, "#");
                positionNE.add(forwardIndex, "#");

                dataBufferWN.insert(reverseIndex, "#");
                positionWN.add(reverseIndex, "#");
                dataBufferWN.insert(forwardIndex, "#");
                positionWN.add(forwardIndex, "#");
                reverseIndex++;
                forwardIndex++;
            }
            forwardIndex += loopValue;
            while(forwardIndex < reverseIndex) {
                dataBufferNE.insert(forwardIndex, "#");
                positionNE.add(forwardIndex, "#");
                dataBufferWN.insert(forwardIndex, "#");
                positionWN.add(forwardIndex, "#");
                forwardIndex += loopValue;
                forwardIndex++;
            }
            dataBufferAll.append(dataBufferWE).append(dataBufferNE).append(dataBufferNS).append(dataBufferWN);
            positionAll.addAll(positionWE);
            positionAll.addAll(positionNE);
            positionAll.addAll(positionNS);
            positionAll.addAll(positionWN);

            line = reader.readLine();
            while (line != null) {
                words.add(line);
                int length = line.length();
                int index = dataBufferAll.indexOf(line);
                String reverse = new StringBuffer(line).reverse().toString();
                line = reader.readLine();
                if(index >= 0) {
                    usedCoordinates.addAll(positionAll.subList(index, index + length));
                    continue;
                }
                index = dataBufferAll.indexOf(reverse);
                if(index >= 0) {
                    usedCoordinates.addAll(positionAll.subList(index, index + length));
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        usedCoordinates.add("#");
        String resultString = "";
        int position = 0;
        for(String value : positionWE) {
            if(!usedCoordinates.contains(value)) {
                resultString += dataBufferWE.charAt(position);
            }
            position++;
        }
        return resultString;
    }
}