import java.io.*;
interface TTTConstants {
  static final int N = 3;
  static final int SIZE = N*N;
  static final byte BLANK = 0;
  static final byte X = 1;
  static final byte O = -X;
}

class IllegalMoveException extends RuntimeException {
  IllegalMoveException(String s) { super("Illegal move: " + s); }
}

class TTTBoard implements /* imports */ TTTConstants {
  byte[] squares;
  int numOfMoves;
  byte next = X;

  TTTBoard() {
    // create an empty board
    squares = new byte[SIZE];
    // default byte value is BLANK
    numOfMoves = 0;
  }

  TTTBoard(TTTBoard s) {
    // clone an existing board
    squares = new byte[SIZE];
    System.arraycopy(s.squares,0,squares,0,SIZE);
    numOfMoves = s.numOfMoves;
    next = s.next;
  }

  void move(int i, int j) {
    int k = index(i,j);
    move(k);
  }

  void move(int k) {
    if (numOfMoves == SIZE) throw new IllegalMoveException(
      "board is full implying that the game is over");
    if (squares[k] != BLANK) 
      throw new IllegalMoveException(
       "square [" + k/N + "," + k%N + "] occupied");
    squares[k] = next;
    next = opposite(next);  
    numOfMoves++;
  }

  byte winner() {
    // not parameterized with respect to N, SIZE
    byte bl = BLANK;
    if (squares[index(0,0)] != bl) {
      if ((squares[index(0,1)] == squares[index(0,0)] &&
	   squares[index(0,2)] == squares[index(0,0)])    ||
	  (squares[index(1,0)] == squares[index(0,0)] &&
	   squares[index(2,0)] == squares[index(0,0)]))    
	return squares[index(0,0)];
    }
    if (squares[index(2,2)] != bl) {	  
      if ((squares[index(2,1)] == squares[index(2,2)] &&
	   squares[index(2,0)] == squares[index(2,2)])    ||
	  (squares[index(1,2)] == squares[index(2,2)] &&
	   squares[index(0,2)] == squares[index(2,2)]))
	return squares[index(2,2)];
    }
    if (squares[index(1,1)] != bl) {	  
      if ((squares[index(0,0)] == squares[index(1,1)] &&
	   squares[index(2,2)] == squares[index(1,1)])    ||
	  (squares[index(0,2)] == squares[index(1,1)] &&
	   squares[index(2,0)] == squares[index(1,1)])    ||
	  (squares[index(0,1)] == squares[index(1,1)] &&
	   squares[index(2,1)] == squares[index(1,1)])    ||
	  (squares[index(1,0)] == squares[index(1,1)] &&
	   squares[index(1,2)] == squares[index(1,1)]))
	return squares[index(1,1)];
    }
    return bl;
  }

  int bestMove() {
    if (numOfMoves == SIZE) throw new RuntimeException("No move is possible");
    int bestValue = next == X ? -1 : 1;
    int bestMove = -1;

    for (int i = 0; i < SIZE; i++)
      if (squares[i] == BLANK) {
	// i is legal move
	TTTBoard b = new TTTBoard(this);
	b.move(i);
	int value = b.eval();
	if (next == X) {
	  if (value > bestValue) {
	    bestMove = i;
	    bestValue = value;
	  }
	}
	else
	  if (value < bestValue) {
	    bestMove = i;
	    bestValue = value;
	  }
      }
    return bestMove;
  }

  int eval() {
    byte win = winner();
    if (win != 0 || numOfMoves == SIZE) return win;

    int bestValue = next == X ? -1 : 1;

    for (int i = 0; i < SIZE; i++)
      if (squares[i] == BLANK) {
	// i is legal move
	TTTBoard b = new TTTBoard(this);
	b.move(i);
	int value = b.eval();
	if (next == X) {
	  if (value > bestValue) {
	    bestValue = value;
	  }
	}
	else
	  if (value < bestValue) {
	    bestValue = value;
	  }
      }
    return bestValue;
  }
    
  static StreamTokenizer in = new StreamTokenizer(
    new BufferedReader(new InputStreamReader(System.in)));

  void play() throws IOException {

    int move;
    while ( numOfMoves < SIZE && winner() == 0) {
      System.out.println("The board position is: \n" + this);
	do {
	  System.out.println("What is your move (a number 0-8)?");
	  int token = in.nextToken();
	  while ((token != in.TT_NUMBER)) token = in.nextToken();
	  move = (int) in.nval;
	} while ((move < 0) || (move > 8) || squares[move] != BLANK);
      move(move);
      System.out.println("The board position after your move is: \n" + this);
      if (numOfMoves < SIZE) {
	int response = bestMove();
	move(response);
	System.out.println(
          "The board position after my response is:\n" + this);
      }
    }
    System.out.println("The game is over. " + (winner() == O ? "I won." :
		       "It was a draw."));
  }


  public String toString() {
    StringBuffer result = new StringBuffer();

    result.append("+-+-+-+\n");
    for (int i = 0; i < N; i++) {
      result.append("|");
      for (int j = 0; j < N; j++) {
	byte sq = squares[index(i,j)];
	result.append( sq == X ? "X|" :
		       sq == O ? "O|" :
		       " |");
      }
      result.append("\n");
      result.append("+-+-+-+\n");
    }
    return result.toString();
  }

  static int index(int i, int j) { return i*N + j; }

  static byte opposite(byte player) { return player == X ? O : X; }

  public static void main(String[] args) throws IOException {
    TTTBoard b1 = new TTTBoard();
    b1.play();
  }
}