using System;

using HtmlAgilityPack;

using System.Linq;

public class Program

{

    public static void Main()

    {

        HtmlWeb web = new HtmlWeb();

        HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();

        doc = web.Load("https://pikabu.ru/@serhiy1994");

        var postDate = doc.DocumentNode.SelectSingleNode("//div[@class='user__info-item']/time");

        Console.WriteLine(postDate.InnerText);

        var nodes = doc.DocumentNode.SelectNodes("//div[@class='story__user user']").Cast<HtmlNode>().ToList();

        foreach (HtmlNode node in nodes)

        {

            // Search within each node using .// notation

            var timeNodes = node.SelectSingleNode(".//div[@class='user__info-item']/time");

            Console.WriteLine(timeNodes.InnerText);

        }

        var single = doc.DocumentNode.SelectSingleNode("//div[@class='story__main']/div[@class='story__footer']/div[@class='story__user user']/div[@class='user__info user__info_left']/div[@class='user__info-item']/time");

        Console.WriteLine(single.InnerText);

    }

}