Вот мой код. показывает Runtime на 4 тесте. не могу разобраться из-за чего.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication4
{
    class Program
    {
        static void Main()
        {
            bool sol;
            string s = Console.ReadLine();
            string[] sp = s.Split(' ');
            int n = int.Parse(sp[0]);
            int m = int.Parse(sp[1]);
            int q = n + 1;
            int q2 = n + 2;
            int p1, p2, p3;
            int[, ,] mas = new int[q2, q2, q2]; // основной массив для работы.
            for (int i = 0; i < m; ++i)   // заполнение массива с клавиатуры.
            {
                string a = Console.ReadLine();
                string[] b = a.Split(' ');
                int[,] c = new int[1, 3]; // интовый массив вводимой строки

                for (int j = 0; j < 3; ++j)
                {
                    c[0, j] = int.Parse(b[j]);
                    if (j == 2)           // когда массив с заполняется, вынимаем индексы и цены.
                    {
                        p1 = c[0, 0];
                        p2 = c[0, 1];
                        p3 = c[0, 2];
                        mas[p2, p1, 0] = p3; // заполняем 0-ой слой основного массива ценами.
                    }
                }
            }
            for (int i = 1; i <= n; ++i)
            {
                for (int j = 1; j <= n; ++j)
                {
                    sol = true;

                    for (int k = 1; k <= n; ++k)
                    {
                        if (mas[k, i, 0] == 0 & mas[k, j, 0] == 0)
                        {
                            mas[j, i, q] = 0;
                            sol = false;
                        }
                        else
                        {
                            if (mas[k, i, 0] <= mas[k, j, 0] & mas[k, i, 0] != 0)
                            {
                                mas[j, i, k] = mas[k, i, 0];
                            }
                            else
                            {
                                mas[j, i, k] = mas[k, j, 0];
                            }
                            if (mas[j, i, q] < mas[j, i, k])
                            {
                                if (sol) { mas[j, i, q] = mas[j, i, k]; }
                            }
                        }
                    }
                    if (mas[0, 0, 0] == 0)
                    {
                        mas[0, 0, 0] = mas[j, i, q];
                    }
                    else
                    {
                        if (mas[j, i, q] > 0)
                        {
                            if (mas[0, 0, 0] >= mas[j, i, q])
                            {
                                mas[0, 0, 0] = mas[j, i, q];
                            }
                        }
                    }
                }
            }



            if (mas[0, 0, 0] < 1)
            {
                Console.WriteLine("No solution");
            }
            else
            {
                Console.WriteLine(mas[0, 0, 0]);
            }
            Console.ReadKey();
        }
    }
}

Can send SMS from a to b through z, (a -> z -> b), or can only
use one direct edge... if possible the cost would be the sum, or the maximum on the path???