diff --git a/react-fb-tictactoe/src/index.js b/react-fb-tictactoe/src/index.js
index fae3e350..a691e908 100644
--- a/react-fb-tictactoe/src/index.js
+++ b/react-fb-tictactoe/src/index.js
@@ -4,5 +4,170 @@ import './index.css';
 import App from './App';
 import registerServiceWorker from './registerServiceWorker';
 
-ReactDOM.render(<App />, document.getElementById('root'));
-registerServiceWorker();
+function Square(props) {
+  return (
+    <button className="square" onClick={props.onClick}>
+      {props.value}
+    </button>
+  );
+}
+  
+  class Board extends React.Component {
+    constructor() {
+      super();
+      this.state = {
+        squares: Array(9).fill(null),
+        xIsNext: true,
+      };
+    }
+
+    handleClick(i) {
+      squares[i] = this.state.xIsNext ? 'X' : 'O';
+      if (calculateWinner(squares) || squares[i]) {
+        return;
+      }
+      const squares = this.state.squares.slice();
+      squares[i] = 'X';
+      this.setState({squares: squares,
+        xIsNext: !this.state.xIsNext,
+      });
+    }
+
+
+    renderSquare(i) {
+      return (
+        <Square
+            value={this.props.squares[i]}
+            onClick={() => this.props.onClick(i)}
+        />
+      );
+    }
+  
+    render() {  
+      return (
+        <div>
+          <div className="board-row">
+            {this.renderSquare(0)}
+            {this.renderSquare(1)}
+            {this.renderSquare(2)}
+          </div>
+          <div className="board-row">
+            {this.renderSquare(3)}
+            {this.renderSquare(4)}
+            {this.renderSquare(5)}
+          </div>
+          <div className="board-row">
+            {this.renderSquare(6)}
+            {this.renderSquare(7)}
+            {this.renderSquare(8)}
+          </div>
+        </div>
+      );
+    }
+  }
+
+  class Game extends React.Component {
+
+    constructor() {
+      super();
+      this.state = {
+        history: [{
+          squares: Array(9).fill(null),
+        }],
+        stepNumber: 0,
+        xIsNext: true,
+      };
+    }
+
+    jumpTo(step) {
+      this.setState({
+        stepNumber: step,
+        xIsNext: (step % 2) === 0,
+      });
+    }
+
+    handleClick(i) {
+      const history = this.state.history.slice(0, this.state.stepNumber + 1);      
+      const current = history[this.state.stepNumber];
+      const squares = current.squares.slice();
+      if (calculateWinner(squares) || squares[i]) {
+        return;
+      }
+      squares[i] = this.state.xIsNext ? 'X' : 'O';
+      this.setState({
+        history: history.concat([{
+          squares: squares,
+        }]),
+        stepNumber: history.length,        
+        xIsNext: !this.state.xIsNext,
+      });
+    }
+
+    render() {
+      const history = this.state.history;
+      const current = history[history.length - 1];
+      const winner = calculateWinner(current.squares);
+      
+      const moves = history.map((step, move) => {
+        const desc = move ?
+          'Move #' + move :
+          'Game start';
+        return (
+          <li key={move}>
+            <a href="#" onClick={() => this.jumpTo(move)}>{desc}</a>
+          </li>
+        );
+      });
+
+
+      let status;
+      if (winner) {
+        status = 'Winner: ' + winner;
+      } else {
+        status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
+      }
+      return (
+        <div className="game">
+          <div className="game-board">
+          <Board
+            squares={current.squares}
+            onClick={(i) => this.handleClick(i)}
+          />
+          </div>
+          <div className="game-info">
+            <div>{status}</div>
+            <ol>{moves}</ol>
+          </div>
+        </div>
+      );
+    }
+  }
+
+  function calculateWinner(squares) {
+    const lines = [
+      [0, 1, 2],
+      [3, 4, 5],
+      [6, 7, 8],
+      [0, 3, 6],
+      [1, 4, 7],
+      [2, 5, 8],
+      [0, 4, 8],
+      [2, 4, 6],
+    ];
+    for (let i = 0; i < lines.length; i++) {
+      const [a, b, c] = lines[i];
+      if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
+        return squares[a];
+      }
+    }
+    return null;
+  }  
+
+
+  // ========================================
+  
+  ReactDOM.render(
+    <Game />,
+    document.getElementById('root')
+  );
+