using System;

using System.Collections.Generic;

using System.Linq;

​

namespace ZvtGenerator2 {

    class Program {

        static string ZvtGenerator(Random rnd, string alphabet, string[] dictionary, double probability)

            => string.Join(" ", Enumerable.Repeat(0, rnd.Next(5) + 1)

                                          .Select(_ => rnd.NextDouble() > probability

                                                       ? string.Concat(Enumerable.Repeat(0, rnd.Next(7) + 1)

                                                                               .Select(_ => alphabet[rnd.Next(alphabet.Length)]))

                                                       : dictionary[rnd.Next(dictionary.Length)])

                          );

        static void Main(string[] args) {

            Random rnd = new Random();

            var dic = new string[] {

                "не тема",

                "тема",

                "ублюдки",

                "типа",

                "топовый"

            };

            Console.WriteLine(ZvtGenerator(rnd, "абвгдежзиклмнуфхцчшщъыьэюя", dic, 0.36));

        }

    }

}

​