using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public class test

    {

        public string teststring { get; set; }

        public string account { get; set; }

        public bool boolfield { get; set;}

        public override string ToString()

            {

                return teststring + " " + account  + " " +boolfield.ToString();

            }

    }

    public static void Main()

    {

        List<test> ll = new List<test>();

        ll.Add(new test{

        teststring = "should be false",

        boolfield = true

        });

        ll.Add(new test{

        teststring = "should be false",

        account = "account",

        boolfield = false

        });

        ll.Add(new test{

        teststring = "should be true",

        boolfield = true

        });

        ll.Add(new test{

        teststring = "fuckyouš",

        boolfield = false

        });

        ll.Add(new test{

        teststring = "fuckyouľ",

        boolfield = false

        });

        ll.Add(new test{

        teststring = "fuckyouwwľ",

        boolfield = true

        });

        var testsss = ll.GroupBy(x=> x.teststring).Where(g => g.Count() > 1).Select(g => new{ g.Key, boolfield = g.All(m => m.boolfield)}).ToList();

        foreach (var item in testsss)

        {

            Console.WriteLine(item.ToString());

        }

        Console.WriteLine("Hello World");

    }

}