JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer" id="countryOuter">
			<input id="country" placeholder="Страна">
		</div>	

		<div class="outer" id="regionOuter">
			<input id="region" placeholder="Регион">
		</div>

		<div class="outer" id="cityOuter">
			<input id="city" placeholder="Город">
		</div>

CSS

.outer{
		margin-bottom: 30px;
	}

JavaScript

$( document ).ready(function() {
	getCountries();

	var countriesArr = [],
			countriesObj = {};
	var regionsArr = [],
			regionsObj = {};	
	var citiesArr = [],
			citiesObj = {};						

	$('#region').attr('disabled', 'disabled');
	$('#city').attr('disabled', 'disabled');

	function getCountries() {
		$.ajax({
	    url: "http://api.vk.com/method/database.getCountries?v=5.69",
	    dataType: "jsonp",
	    success: function( data ) {
				var countriesRaw = data['response']['items'];
			  console.log( countriesRaw );

			  countriesArr = countriesRaw.map(function(country) {
			  	return country.title;
			  });
			  console.log(countriesArr);

			  countriesRaw.forEach(function(country) {
			  	countriesObj[country.title] = country.id;
			  });
			  console.log(countriesObj);

				document.getElementById('countryOuter').style.display = 'block';
			  
				$( "#country" ).autocomplete({
					delay: 0.5,
					source: countriesArr,
					select: function(event, ui) {
						$('#country').attr('disabled', 'disabled');
						$('#region').removeAttr('disabled');					
	          console.log(event, countriesObj[ui.item.label]);
	          getRegions(countriesObj[ui.item.label]);
		      }
				});	
	    }		    
		});
	};

	function getRegions(countryId) {
		$.ajax({
	    url: "http://api.vk.com/method/database.getRegions?v=5.5&country_id=" + countryId,
	    dataType: "jsonp",
	    success: function( data ) {
				var regionsRaw = data['response']['items'];
			  console.log( regionsRaw );

			  regionsArr = regionsRaw.map(function(region) {
			  	return region.title;
			  });
			  console.log(regionsArr);

			  regionsRaw.forEach(function(region) {
			  	regionsObj[region.title] = region.id;
			  });
			  console.log(regionsObj);

			  console.log('____countryId', countryId);

				$( "#region" ).autocomplete({
					delay: 0.5,
					source: regionsArr,
					select: function(event, ui) {
						$('#region').attr('disabled', 'disabled');
						$('#city').removeAttr('disabled');					
	...