using System;

public class Program

{

    const int CONDITION_TO_SWAP = 2;

    public static void Main()

    {

            Console.WriteLine(StringSwap("1f gsg", 3));

            Console.WriteLine(StringSwap("1f gsg", 5));

            Console.WriteLine(StringSwap("Anton Nazar", 5));

            Console.WriteLine(StringSwap("54knknj52", 2));

            Console.WriteLine(StringSwap("kc", 12));

            Console.WriteLine(StringSwap("1223", 12));

​

            Console.WriteLine(DigitsSwap(1223, 2));

            Console.WriteLine(DigitsSwap(654213168, 1));

            Console.WriteLine(DigitsSwap(165164, 2));

            Console.WriteLine(DigitsSwap(1223, 14));

            Console.WriteLine(DigitsSwap(100231556, 4));    

        //here are some valid cases:

        Console.WriteLine(DigitsSwap(100, 2));

        Console.WriteLine(StringSwap("100", 2));

    }

    /// <summary>

        /// Приймає параметр string і переставляє місцями перші N букви з N останніми

        /// </summary>

        /// <param name="anyString">Enter any string</param>

        /// <param name="numberOfSymbolsToSwap">Number of symbols to swap at start and end</param>

        /// <returns>Returns swapped string</returns>

        static string StringSwap(string anyString, int numberOfSymbolsToSwap)

        {

            //TODO

            // 1st - why do U use harcoded value of 2? 

            // what if I want to replace first 5 chars with last 5 chars?

            // or first char with last?

            if (anyString.Length < CONDITION_TO_SWAP * numberOfSymbolsToSwap)

            {

                return "Your PARAMETER length is smaller than number of symbols to swap";

            }

​

            string endPart = anyString.Substring(0, numberOfSymbolsToSwap);

            string middlePart = anyString.Substring(numberOfSymbolsToSwap, anyString.Length - 2 * numberOfSymbolsToSwap);

            string startPart = anyString.Substring(anyString.Length - numberOfSymbolsToSwap, numberOfSymbolsToSwap);

​

            return startPart + middlePart + endPart;

        }

​

        /// <summary>

        /// Приймає параметр int і переставляє місцями перші N цифр з N останніми

        /// </summary>

        /// <param name="anyDigits">Enter digits</param>

        /// <param name="numberOfSymbolsToSwap">Number of symbols to swap at start and end</param>

        /// <returns>Returns swapped digits</returns>

        static int DigitsSwap(int anyDigits, int numberOfSymbolsToSwap)

        {

            string stringOfDigits = Convert.ToString(anyDigits);

​

            //TODO: see above

            if (stringOfDigits.Length < CONDITION_TO_SWAP * numberOfSymbolsToSwap)

            {

                Console.WriteLine("Your length is smaller than number of symbols to swap");

                return 0;

            }

​

            return Convert.ToInt32(StringSwap(stringOfDigits, numberOfSymbolsToSwap));

        }

}