text: import React from 'react';
  import ReactDOM from 'react-dom';
  import {IndexRoute, Route, Router, browserHistory} from 'react-router';
  
  import Error from './container/Error';
  import Frame from './container/Frame';
  import Home from './container/Home';
  import './index.css';
  
  ReactDOM.render(
    <Router history={browserHistory}>
      <Route path="/arithmetic" component={Frame}>
        <IndexRoute component={Home} />
        <Route path="*" component={Error} />
      </Route>
    </Router>,
    document.getElementById('root')
  );
  