diff --git a/src/App.tsx b/src/App.tsx
index 2cdd87e..684a1d0 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -2,29 +2,78 @@ import React from 'react';
 import ReactDOM from 'react-dom';
 import './App.css';
 
+interface SquareGameProps {
+  value: any
+  onClick: Function
+}
+
+interface SquareGameState{
+  value: any
+
+  // whatever other state we add here
+}
+
+interface BoardGameProps {
+  
+}
+
+interface BoardGameState {
+  squares: any
+  xIsNext: boolean
+}
+
 function App() {
   return (
     <Game />
   );
 }
 
-class Square extends React.Component {
+class Square extends React.Component<SquareGameProps, SquareGameState> {
   render() {
     return(
-      <button className='square'>
+      <button className='square' onClick={() => { this.props.onClick() }}>
         { this.props.value }
       </button>
     );
   }
 }
 
-class Board extends React.Component {
-  renderSquare(i: any) {
-    return <Square value={i} />
+class Board extends React.Component<BoardGameProps, BoardGameState> {
+  constructor(props: any) {
+    super(props);
+
+    this.state = {
+      squares: Array(9).fill(null),
+      xIsNext: true,
+    }
+  }
+
+  handleClick(i: string | number) {
+    const squares = this.state.squares.slice();
+    if (calculateWinner(squares) || squares[i]) {
+      return;
+    }
+    squares[i] = this.state.xIsNext ? 'X' : 'O';
+    this.setState({
+      squares: squares,
+      xIsNext: !this.state.xIsNext,
+    });
+  }
+
+  renderSquare(i: string | number) {
+    return <Square value={this.state.squares[i]} onClick={() => this.handleClick(i)}/>
   }
 
   render() {
-    const status = 'Next player: X';
+    const winner = calculateWinner(this.state.squares);
+    let status;
+
+    if (winner) {
+      status = 'Winner: ' + winner;
+    }
+    else {
+      status = `Next player: ${this.state.xIsNext ? 'X' : 'O'}`;
+    }
 
     return(
       <div>
@@ -64,4 +113,28 @@ class Game extends React.Component {
     );
   }
 }
+
+function calculateWinner(squares: any) {
+  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],
+  ];
+
+  lines.forEach((i: any) => {
+    const [a, b, c] = i;
+
+    if (squares[a] && squares[b] === squares[a] && squares[c]) {
+      return squares[a];
+    }
+  });
+
+  return null;
+}
+
 export default App;