using System.Collections.Generic;
public static void Main()
Console.WriteLine("Hello World");
List<(string, string)> travels=new List<(string, string)>()
("A", "B"), ("A", "C"), ("B", "C"), ("C", "A")
Console.WriteLine(string.Join(",", FindFlights(travels, "A")));
public static List<string> FindFlights(List<(string, string)> travels, string starting)
Dictionary<string, List<string>> dict = new Dictionary<string, List<string>>();
List<string> visited = new List<string>();
foreach((string, string) travel in travels)
if(!dict.ContainsKey(travel.Item1))
dict.Add(travel.Item1, new List<string>());
dict[travel.Item1].Add(travel.Item2);
dict[travel.Item1].Sort();
if(!dict.ContainsKey(next) || dict[next].Count==0)
string temp = dict[next][0];