using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace StringEdit
{
    class Program
    {
        static void Main(string[] args)
        {
            string sentenceCorrection;
            int incorrectIndex = 0;
            char replacementChar;
            int sentenceLength = 0;

            Program FixTypo = new Program();

            Console.WriteLine("Which sentence do you want correcting?");
            sentenceCorrection = Console.ReadLine();
            sentenceCorrection = sentenceCorrection.ToLower();

            sentenceLength = sentenceCorrection.Length - 1;

            Console.WriteLine("At which index do you want it correcting? (maximum " + sentenceLength + ")");
            incorrectIndex = int.Parse(Console.ReadLine());

            Console.WriteLine("What do you want to change the character to?");
            replacementChar = char.Parse(Console.ReadLine());

            FixTypo.FixTypo(sentenceCorrection, incorrectIndex, replacementChar);



        }

            public string FixTypo(string sentenceCorrection, int incorrectIndex, char replacementChar)
        {
            string correctedSentence = "";
            char indexLetter;
            indexLetter = sentenceCorrection[incorrectIndex];

            correctedSentence = sentenceCorrection.Replace(indexLetter, replacementChar);

            Console.WriteLine("The corrected sentence is as follows: ");
            Console.WriteLine(correctedSentence);

            return correctedSentence;
        }


        }
    }