using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using CsvHelper;

public static class Program

{

    private const string CsvData = @"name,state,ClosetSize,childGender

Hank,OK,2,M

Hank,OK,1,F

Wilbur,TX,1,F

Wilbur,TX,2,F

Tom,CA,3,M

Tom,CA,4,M

Zed,VT,1,M

Zed,VT,2,M

Zed,VT,3,F";

    public static void Main()

    {

        Process(CsvData);

    }

    private static void Process(string inputData)

    {

        IReadOnlyCollection<SourceRecord> input = SourceRecord.Parse(inputData);

        IEnumerable<OutputRecord> output = input

            .GroupBy(r => new { r.name, r.state })

            .Where(g => g.Any(r => r.childGender == 'M') && g.Any(r => r.childGender == 'F'))

            .Select(g => new OutputRecord

            {

                name = g.Key.name,

                state = g.Key.state,

                ClosetSize = g.Sum(r => r.ClosetSize),

            });

        OutputRecord.Save(Console.Out, output);

    }

}

​

struct SourceRecord

{

    public string name { get; set; }

    public string state { get; set; }

    public int ClosetSize { get; set; }

    public char childGender { get; set; }

    public static IReadOnlyCollection<SourceRecord> Load(TextReader reader)

    {

        var csv = new CsvReader(reader);

        return csv.GetRecords<SourceRecord>().ToList();

    }

    public static IReadOnlyCollection<SourceRecord> LoadFrom(string fileName)

    {

        using (var reader = File.OpenText(fileName))

        {

            return Load(reader);

        }

    }

    public static IReadOnlyCollection<SourceRecord> Parse(string input)

    {

        using (var reader = new StringReader(input))

        {

            return Load(reader);

        }

    }

}

struct OutputRecord

{

    public string name { get; set; }

    public string state { get; set; }

    public int ClosetSize { get; set; }

    public static void Save(TextWriter writer, IEnumerable<OutputRecord> records)

    {

        var csv = new CsvWriter(writer);

        csv.WriteRecords(records);

    }

    public static void SaveTo(string fileName, IEnumerable<OutputRecord> records)

    {

        using (var writer = new StreamWriter(fileName))

        {

            Save(writer, records);

        }

    }

}