Population_Counter

using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Text;

class PopulationCounter
{
    static void Main()
    {
        var populationStructure = new Dictionary<string, Dictionary<string, int>>();
        string inputline = Console.ReadLine();

        while (inputline != "report")
        {
            string[] tokens = inputline.Split('|');
            string city = tokens[0];
            string country = tokens[1];
            int population = int.Parse(tokens[2]);

            if (populationStructure.ContainsKey(country))
            {
                if (populationStructure[country].ContainsKey(city))
                {
                    populationStructure[country][city] += population;
                }
                else
                {
                    populationStructure[country][city] = population;
                }
            }
            else
            {
                populationStructure[country] = new Dictionary<string, int>();
                populationStructure[country][city] = population;
            }

            inputline = Console.ReadLine();
        }

        var sortedCountries =
            from country in populationStructure
            orderby TotatCountryPopulation(country.Value) descending
            select country;

        foreach (var countryKeyValuePair in sortedCountries)
        {
            var totalPopulation = TotatCountryPopulation(countryKeyValuePair.Value);
            Console.WriteLine($"{countryKeyValuePair.Key} (total population: {totalPopulation})");

            var sortedCities =
                from city in countryKeyValuePair.Value
                orderby city.Value descending
                select city;

            foreach (var cityKeyValuePair in sortedCities)
            {
                Console.WriteLine($"=>{cityKeyValuePair.Key}: {cityKeyValuePair.Value}");
            }
        }
    }

    public static BigInteger TotatCountryPopulation(Dictionary<string, int> innerDictionary)
    {
        BigInteger result = 0;
        foreach (var keyValuePair in innerDictionary)
        {
            result += keyValuePair.Value;
        }
        return result;
    }
}