Top product you are given a list of product sales.

string[] lines = data.Split(new[] { " top " }, StringSplitOptions.None);

using System;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int t = int.Parse(Console.ReadLine());
            List<string> output = new List<string>();
            for (int i = 0; i < t; i++)
            {
                List<string> prodDetails = new List<string>();
                int c = int.Parse(Console.ReadLine());
                for (int j = 0; j < c; j++)
                {
                    prodDetails.Add(Console.ReadLine());
                }
                GetTopProductDetails(prodDetails, output);
            }
            output.ForEach(x => Console.WriteLine(x));
        }

        private static List<string> GetTopProductDetails(List<string> prodDetails, List<string> output)
        {
            Dictionary<string, int=""> keyValuePairs = new Dictionary<string, int="">();
            for (int i = 0; i < prodDetails.Count; i++)
            {
                if (prodDetails[i].ToLower() != "top")
                {
                    string[] x = prodDetails[i].Split(' ');
                    string P = x[0];
                    int U = int.Parse(x[1]);
                    if (keyValuePairs.ContainsKey(P))
                    {
                        int unit = 0;
                        keyValuePairs.TryGetValue(P, out unit);
                        keyValuePairs[P] = unit + U;
                    }
                    else
                    {
                        keyValuePairs.Add(P, U);
                    }
                }
                else
                {
                    var valuesList = keyValuePairs.Where(x => x.Value == keyValuePairs.Values.Max()).Select(v => v.Key).OrderBy(y => y).ToList();
                    string disp = string.Join(" ", valuesList);
                    output.Add(disp);
                }
            }
            return output;
        }
    }
}