Vladko's Notebook (C#)

using System;
using System.Collections.Generic;
using System.Text;

public class VladkosNotebook
{
    public static void Main()
    {
        var notebook = new SortedDictionary<string, Dictionary<string, dynamic>>();
        string input = Console.ReadLine();

        while (input != "END")
        {
            string[] tokens = input.Split('|');

            string color = tokens[0];
            string property = tokens[1];
            string value = tokens[2];

            if (!notebook.ContainsKey(color))
            {
                notebook.Add(color, new Dictionary<string, dynamic>());
                notebook[color].Add("opponents", new List<string>());
                notebook[color].Add("wins", 0);
                notebook[color].Add("losses", 0);
            }

            if (property == "win")
            {
                notebook[color]["wins"]++;
                notebook[color]["opponents"].Add(value);
            }
            else if (property == "loss")
            {
                notebook[color]["losses"]++;
                notebook[color]["opponents"].Add(value);
            }
            else if (property == "age" && !notebook[color].ContainsKey("age"))
            {
                notebook[color].Add("age", value);
            }
            else if(property == "name" && !notebook[color].ContainsKey("name"))
            {
                notebook[color].Add("name", value);
            }

            input = Console.ReadLine();
        }

        var result = new SortedDictionary<string, Dictionary<string, dynamic>>();

        foreach (var entry in notebook)
        {
            if (!entry.Value.ContainsKey("name") || !entry.Value.ContainsKey("age"))
            {
                continue;
            }

            var rank = ((double)entry.Value["wins"] + 1) / (entry.Value["losses"] + 1);
            rank = string.Format("{0:F2}", rank);

            var opponents = entry.Value["opponents"].ToArray();
            Array.Sort(opponents, StringComparer.Ordinal);

            result.Add(entry.Key, new Dictionary<string, dynamic>());

            result[entry.Key].Add("age", entry.Value["age"]);
            result[entry.Key].Add("name", entry.Value["name"]);
            result[entry.Key].Add("opponents", opponents);
            result[entry.Key].Add("rank", rank.ToString());
        }

        StringBuilder output = new StringBuilder();
        output.Append("{");

        foreach (var pair in result)
        {
            output.AppendFormat("\"{0}\":{{", pair.Key);
            output.AppendFormat("\"age\":\"{0}\",", pair.Value["age"]);
            output.AppendFormat("\"name\":\"{0}\",", pair.Value["name"]);

            var opponents = string.Join(",", pair.Value["opponents"]);
            opponents = opponents.Replace(",", "\",\"");

            if (opponents.Length > 0)
            {
                opponents = string.Format("[\"{0}\"]", opponents);
            }
            else
            {
                opponents = "[]";
            }

            output.AppendFormat("\"opponents\":{0},", opponents);
            output.AppendFormat("\"rank\":\"{0}\"", pair.Value["rank"]);
            output.Append("},");
        }

        if (output.Length > 1)
        {
            output.Remove(output.Length - 1, 1);
        }

        output.Append("}");

        Console.WriteLine(output);
    }
}