1. Largest Common End

namespace ConsoleApp1
{
    using System;

    public class StartUp
    {
        public static void Main()
        {
            char[] splitSymbols = new[] { ' ' };
            string[] firstWords = SplitString(Console.ReadLine(), splitSymbols);
            string[] secondWords = SplitString(Console.ReadLine(), splitSymbols);

            int leftCompare = CompareStringArrays(firstWords, secondWords);

            Reverse(firstWords);
            Reverse(secondWords);
            int rightCompare = CompareStringArrays(firstWords, secondWords);

            Console.WriteLine(Math.Max(leftCompare, rightCompare));
        }

        public static void Reverse(string[] arrayToReverse)
        {
            for (int currentIndex = 0; currentIndex < arrayToReverse.Length / 2; currentIndex++)
            {
                int lastIndex = arrayToReverse.Length - 1 - currentIndex;
                string holder = arrayToReverse[lastIndex];
                arrayToReverse[lastIndex] = arrayToReverse[currentIndex];
                arrayToReverse[currentIndex] = holder;
            }
        }

        public static int CompareStringArrays(string[] firstArray, string[] secondArray)
        {
            int counter = 0;

            int smallerLength = Math.Min(firstArray.Length, secondArray.Length);
            for (int currentElement = 0; currentElement < smallerLength; currentElement++)
            {
                string firstElement = firstArray[currentElement];
                string secondElement = secondArray[currentElement];

                if (firstElement.Equals(secondElement))
                {
                    counter++;
                }
                else
                {
                    break;
                }
            }

            return counter;
        }

        public static string[] SplitString(string stringToSplit, char[] splitSymbols)
        {
            return stringToSplit.Split(splitSymbols, StringSplitOptions.RemoveEmptyEntries);
        }
    }
}