ArrayAbsurdity.Program.Main C# (CSharp) Method

        static void Main(string[] args)
        {
            //using (StreamReader reader = File.OpenText(args[0]))
            //    while (!reader.EndOfStream)
            //    {
            string line = Console.ReadLine();
            //if(line == null)
            //    continue;
            string[] input = line.Split(';');
            int[] n = input[1].Split(',').Select(x => int.Parse(x)).ToArray<int>();
            int[] res = new int[int.Parse(input[0])];
            int result = 0;
            for (int i = 0; i < n.Length; i++)
            {
                if (res[n[i]] > 1)
                    result = n[i];
                else
                    res[n[i]]++;
            }
            Console.WriteLine(result);
                //}
            Console.ReadLine();
        }