using System;

using System.Collections.Generic;

​

namespace KataTrain190319

{

    class Program

    {

        static int Factorial(int i)

        {

            if (i < 0)

                throw new Exception("Welcome to the rice fields motherfucker");

            int result = 1;

            for (int j = 2; j <= i; j++)

                result *= j;

            return result;

        }

        static void Main(string[] args)

        {

            int t = 174, k = 3;

            List<int> ls = new List<int>{ 50 };

            int n = ls.Count;

​

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

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

            for (int i = 0; i < k; i++)

            {

                lsIndexes.Add(i);

                lsPermutationSums.Add(0);

                lsPermutationSums[0] += ls[i];

            }

​

            long counter = Factorial(n) / (Factorial(n - k)*Factorial(k));

            /*

            foreach (var inte in lsIndexes)

                Console.WriteLine(inte);

                */

            int index = 1;

            bool shift = false;

            while(index < counter)

            {

                for(int i = k - 1; i >= 0; i--)

                {

                    if(i == k - 1 && lsIndexes[i] != n - k + i)

                    {

                        lsIndexes[i]++;

                        shift = false;

                    }

                    else if(shift == true && lsIndexes[i] != n - k + i && lsIndexes[i + 1] == n - k + i + 1)

                    {

                        lsIndexes[i]++;

                        for(int j = i + 1; j < k; j++)

                        {

                            lsIndexes[j] = lsIndexes[j - 1] + 1;

                        }

                        shift = false;

                    }

                    else if (lsIndexes[i] == n - k + i)

                    {

                        shift = true;

                    }

                }

                int l = 0;

                lsPermutationSums.Add(l);

                foreach (var j in lsIndexes)

                    lsPermutationSums[index] += ls[j];

                index++;

                /*

                foreach (var inte in lsIndexes)

                    Console.WriteLine(inte);

                Console.WriteLine("x");*/

​

            }

            lsPermutationSums.Sort();

            int? res;

            for (int i = lsPermutationSums.Count - 1; i >= 0; i--)

                if (lsPermutationSums[i] <= t)

                {

                    res = lsPermutationSums[i];

                    break;

                }

​

        }

    }

}