using System;

using System.Collections.Generic;       

​

class Program

    {

        private const string testInput = @"1

                                           8 4

                                           2 6 9

                                           8 5 9 3";

​

        private const string input = @"215

                                       193 124

                                       117 237 442

                                       218 935 347 235

                                       320 804 522 417 345

                                       229 601 723 835 133 124

                                       248 202 277 433 207 263 257

                                       359 464 504 528 516 716 871 182

                                       461 441 426 656 863 560 380 171 923

                                       381 348 573 533 447 632 387 176 975 449

                                       223 711 445 645 245 543 931 532 937 541 444

                                       330 131 333 928 377 733 017 778 839 168 197 197

                                       131 171 522 137 217 224 291 413 528 520 227 229 928

                                       223 626 034 683 839 053 627 310 713 999 629 817 410 121

                                       924 622 911 233 325 139 721 218 253 223 107 233 230 124 233";

​

        static void Main(string[] args)

        {

            List<string> pyramidList = InputToList(testInput);

            int lineCount = FindLineCount(pyramidList);

            int[,] pyramidArray = ListToArray(pyramidList, lineCount);

            List<int> way = PathFinder(pyramidArray, lineCount);

​

            int sum = 0;

            foreach (var item in way)

            {

                sum += item;

                Console.WriteLine(item);

            }

            Console.WriteLine("Sum: "+ sum);        

​

        }

​

        private static List<string> InputToList(string input)

        {

            string[] inputArray = input.Split("\n");

​

            List<string> allNumberLine = new List<string>();

            foreach (var item in inputArray)

            {

                if (item != "\n" || item != " ")

                {

                    allNumberLine.Add(item.Trim(' '));

                }

            }

​

            List<string> allNumber = new List<string>();

            foreach (var line in allNumberLine)

            {

                foreach (var number in line.Split(" "))

                {

                    allNumber.Add(number);

                }

            }

​

            return allNumber;

        }

​

        private static int FindLineCount(List<string> pyramidList)

        {

            int numberCount = 0;

            int lineCount = 0;

            for (int i = 0; i < pyramidList.Count; i++)

            {

                numberCount += i;

                if (numberCount == pyramidList.Count)

                {

                    lineCount = i;

                    break;

                }

            }

            return lineCount;

        }

​

        private static int[,] ListToArray(List<string> pyramidList, int lineCount)

        {

            int[,] pyramidArray = new int[lineCount, lineCount];

            int numberCounter = 0;

            for (int x = 0; x < lineCount; x++)

            {

                for (int y = 0; y <= x; y++)

                {

                    pyramidArray[x, y] = int.Parse(pyramidList[numberCounter]);

                    numberCounter += 1;

                }

            }

            return pyramidArray;

        }

​

        public static bool IsPrime(int number)

        {

            if (number <= 1) return false;

            if (number == 2) return true;

            if (number % 2 == 0) return false;

​

            var boundary = (int)Math.Floor(Math.Sqrt(number));

​

            for (int i = 3; i <= boundary; i += 2)

                if (number % i == 0)

                    return false;

​

            return true;

        }

​

        public static List<int> PathFinder(int[,] pyramidArray, int lineCount)

        {

            int sum = 0;

            List<int> way = new List<int>();

            int currentX = 0;

            int currentY = 0;

            way.Add(pyramidArray[currentX, currentY]);

            for (int x = 0; x <= lineCount; x++)

            {

                bool updateCurrentIndex = true;

                int nextNumber = 0;

​

                if (currentX + 1 >= lineCount)

                {

                    break;

                }

​

                if (!IsPrime(pyramidArray[currentX + 1, currentY]) && IsPrime(pyramidArray[currentX + 1, currentY + 1]))

                {

                    nextNumber = pyramidArray[currentX + 1, currentY];

                    updateCurrentIndex = true;

                }

                else if (!IsPrime(pyramidArray[currentX + 1, currentY + 1]) && IsPrime(pyramidArray[currentX + 1, currentY]))

                {

                    nextNumber = pyramidArray[currentX + 1, currentY + 1];

                    updateCurrentIndex = false;

                }

                else if (!IsPrime(pyramidArray[currentX + 1, currentY]) && !IsPrime(pyramidArray[currentX + 1, currentY + 1]))

                {

                    if (pyramidArray[currentX + 1, currentY] > pyramidArray[currentX + 1, currentY + 1])

                    {

                        nextNumber = pyramidArray[currentX + 1, currentY];

                        updateCurrentIndex = true;

                    }

                    else

                    {

                        nextNumber = pyramidArray[currentX + 1, currentY + 1];

                        updateCurrentIndex = false;

                    }

                }

​

                way.Add(nextNumber);

​

                if (updateCurrentIndex)

                {

                    currentX = currentX + 1;

                }

                else

                {

                    currentX = currentX + 1;

                    currentY = currentY + 1;

                }

​

            }

​

            return way;

        }

​

    }