text: var exp = require("express");
  
  var app = exp();
  
  
  app.get("/", function(req, res){
  	res.send("<html><body><h1>You called root path</h1></body></html>");
  });
  
  app.get("/data", function(req, res){
  	res.send("You called data");
  });
  
  app.get("/download", function(req, res){
  	res.download("./package.json", function(){
  		console.log("download is over");
  	});
  });
  
  //var port =  4000;
  
  var port = process.env.port || 3000;
  
  app.listen(port, function(){
  	console.log("Server is ON at " + port);
  });