// 4
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Zad4
{
    public class Program
    {
        public static void Main()
        {
            var numberOfElements = int.Parse(Console.ReadLine());
            var numbers = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToArray();
            Console.Write("\n");
            Array.ForEach(ReverseArray(numberOfElements, numbers), number => Console.Write($"{number} "));
            Console.ReadKey();
        }

        public static int[] ReverseArray(int numberOfElements, int[] numbers)
        {
            var newArray = new int[numberOfElements];

            for (int i = 0; i < numberOfElements; i++)
            {
                newArray[numberOfElements - i - 1] = numbers[i];
            }
            return newArray;
        }
    }
}

// 5
using System;
using System.Text.RegularExpressions;

namespace Zad5
{
    public class Program
    {
        public static void Main()
        {
            Regex rgx = new Regex("[^a-z -]");

            var text = rgx.Replace(Console.ReadLine().ToLower(), "");
            Console.WriteLine(Palindrome(text));
            Console.ReadKey();
        }

        public static string Palindrome(string text)
        {
            for (int i = 0, j = text.Length - 1; i < j; i++, j--)
            {
                if (text[i] != text[j]) return "NO";
            }
            return "YES";
        }
    }
}

// 6

using System;
using System.Collections.Generic;
using System.Linq;

namespace Zad6
{
    class Program
    {
        static void Main(string[] args)
        {
            var numbers1 = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToList();
            var numbers2 = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToList();
            Console.WriteLine(Permutation(numbers1, numbers2));
            Console.ReadKey();
        }

        static string Permutation(List<int> numbers1, List<int> numbers2)
        {
            if (numbers1.Count != numbers2.Count) return "NO";
            foreach (var number in numbers2)
            {
                var index = numbers1.IndexOf(number);
                if (index > -1) numbers1.RemoveAt(index);
            }
            if (numbers1.Count > 0) return "NO";
            return "YES";
        }
    }
}


// 7
using System;
using System.Collections.Generic;
using System.Linq;

namespace Zad7
{
    class Program
    {
        static void Main(string[] args)
        {
            var numbers = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToList();
            var powersOfTwo = new List<int>();
            var greatestPowerOfTwo = 0;

            foreach (var number in numbers)
            {
                var power = 1;
                while (true)
                {
                    if (number < power) break;
                    if (number == power && power > greatestPowerOfTwo) greatestPowerOfTwo = number;
                    power *= 2;
                }
            }

            var powerOfTwo = 1;
            while (true)
            {
                if (powerOfTwo <= greatestPowerOfTwo) powersOfTwo.Add(powerOfTwo);
                else break;
                powerOfTwo *= 2;
            }

            for (int i = 0; i < powersOfTwo.Count; i++)
            {
                if (i < powersOfTwo.Count - 1) Console.Write($"{powersOfTwo[i]}, ");
                else Console.Write($"{powersOfTwo[i]}");
            }

            Console.ReadKey();
        }
    }
}

// 8
using System;
using System.Collections.Generic;
using System.Linq;

namespace Zad8
{
    class Program
    {
        static void Main(string[] args)
        {
            var numberOfLines = int.Parse(Console.ReadLine());
            var listOfLines = new List<int[]>();

            for (int i = 0; i < numberOfLines; i++)
            {
                listOfLines.Add(Console.ReadLine()
                    .Split(' ')
                    .Select(value => int.Parse(value))
                    .ToArray());

                if (listOfLines[listOfLines.Count - 1].Length != 2)
                {
                    Console.WriteLine("Wrong input");
                    Console.ReadKey();
                    Environment.Exit(1);
                }
            }

            var numberOfPrimes = 0;
            foreach (var line in listOfLines)
            {
                var n = line[0];
                var m = line[1];
                for (; n <= m; n++)
                {
                    if (IsPrime(n)) numberOfPrimes++;
                }
                Console.Write($"{numberOfPrimes} ");
            }

            Console.ReadKey();
        }

        static bool IsPrime(int n)
        {
            if (n <= 3) return n > 1;
            else if (n % 2 == 0 || n % 3 == 0) return false;
            var i = 5;
            while (i * i <= n)
            {
                if (n % i == 0 || n % (i + 2) == 0) return false;
                i += 6;
            }
            return true;
        }
    }
}

// 11
using System;
using System.Collections.Generic;
using System.Linq;

namespace Zad_11
{
    class Program
    {
        static void Main(string[] args)
        {
            var numberOfElements = int.Parse(Console.ReadLine());
            var numbers = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToArray();
            var digits = new List<int>();

            foreach (var number in numbers)
            {
                var copyOfNumber = number;
                while (true)
                {
                    digits.Add(copyOfNumber % 10);
                    copyOfNumber /= 10;
                    if (copyOfNumber == 0) break;
                }
            }

            Console.WriteLine(FindTheMostRepeatedNumber(digits));

            Console.ReadKey();
        }

        static int FindTheMostRepeatedNumber(IEnumerable<int> numbers)
        {
            var repeatedNumbers = new Dictionary<int, int>();

            foreach (var number in numbers)
            {
                if (!repeatedNumbers.ContainsKey(number)) repeatedNumbers.Add(number, 0);
                repeatedNumbers[number]++;
            }

            var biggestNumber = repeatedNumbers.Aggregate((acc, cur) => cur.Value > acc.Value || cur.Key > acc.Key ? cur : acc).Key;

            return biggestNumber;
        }
    }
}

// 12
using System;
using System.Linq;

namespace Zad12
{
    class Program
    {
        static void Main(string[] args)
        {
            var numberOfElements = int.Parse(Console.ReadLine());
            var numbers = Console.ReadLine()
                .Split(' ')
                .Select(value => int.Parse(value))
                .ToArray();
            Console.WriteLine(GreatestSumOfDigits(numbers));
            Console.ReadKey();
        }

        static int GreatestSumOfDigits(int[] numbers)
        {
            var greatest = numbers.Aggregate((number: -1, sumOfDigits: -1), (acc, currentNumber) =>
            {
                var currentSum = 0;
                var currentNumberCounter = currentNumber;
                while (true)
                {
                    currentSum += currentNumberCounter % 10;
                    currentNumberCounter /= 10;
                    if (currentNumberCounter == 0) break;
                }

                if (acc.sumOfDigits == currentSum)
                {
                    return acc.number > currentNumber ? acc : (number: currentNumber, sumOfDigits: currentSum);
                }
                return acc.sumOfDigits > currentSum ? acc : (number: currentNumber, sumOfDigits: currentSum);
            }).number;

            return Array.IndexOf(numbers, greatest);
        }
    }
}