block9.js

// Main.js
import React from 'react';
import { Link } from '@reach/router';

import logo from './logo.svg';
import './App.css';

const Main = () => (
  <header className="App-header">
    <Link to="/split">
      <img src={logo} className="App-logo" alt="logo" />
    </Link>
    
    ...
  </header>
);

export default Main;