using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        //Summarising Text

        var sentence = "This is going to be a really really really really really long text.";

​

        const int maxLenght = 20;

​

        //If text's lenght is less than 20 char then display else...

     if (sentence.Length < maxLenght)

            Console.WriteLine(sentence);

     else

        {

            // sentence.Substring(0,maxLenght)  This could cut off a word in half, so not used.

            string[] words = sentence.Split(' ');

            var totalChar = 0;

            var summaryWords = new List<string>();

​

            //The below loops through all words and adds on total char to the variable.

            //Once totalChar reaches over maxLenght, break the loop.

            foreach (var word in words)

            {

                summaryWords.Add(word);

                totalChar = totalChar + word.Length +1 ;

                if (totalChar > maxLenght)

                    break;

            }

            var summary = String.Join(" ", summaryWords) + "....";

            Console.WriteLine(summary);

     }

    }

}