const express = require('express');
const app = express();
const PORT = 3000;
app.get('/', (req, res) => {
  res.send('Hello World!');
});
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

This creates a basic server that listens on port 3000 and responds with "Hello World!" when accessing the root route.