After effects жутко лагает и тормозит

и в чем вопрос?

Так не лезь в прогу, раз всё так херово, что за мазохизм.

Последние версии тормозят. 2017 и ниже тормозят меньше.

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

namespace Evdak
{
class Student
{
public string Lastname { get; set; }
public string Subject { get; set; }
private int score;
public int Score
{
get { return score; }
set
{
if (value > 0)
{
this.score = value;
}
}
}

public Student(string lastname, string subject, int score)
{
this.Lastname = lastname;
this.Subject = subject;
this.Score = score;
}
public Student()
{
this.Lastname = "Фамилия";
this.Subject = "Дисциплина";
this.Score = 5;
}
public void ShowPerson()
{
Console.WriteLine();
Console.WriteLine("Фамилия : " + this.Lastname);
Console.WriteLine("Дисциплина : " + this.Subject);
Console.WriteLine("Оценка : " + this.Score);
Console.WriteLine();
}
}
class Projecion : Student
{
public string Good { get; set; }
public Projecion(Student student)
{
this.Lastname = student.Lastname;
this.Subject = student.Subject;
this.Score = student.Score;

}
}
class Other
{
public List Learners { get; set; }

public List sortbyScore()
{
return (from people in Learners orderby people.Score select people).ToList();
}

public IEnumerable groupbySubject()
{
return from student in Learners group student by student.Subject;
}
public void ShowGroup(IEnumerable Group)
{
foreach (IGrouping a in Group)
{
Console.WriteLine(a.Key);
foreach (Student student in a)
{
Console.WriteLine(student.Lastname + " " + student.Score);
Console.WriteLine();
}
}
}

public List Join(List persons)
{
Learners = Learners.Concat(persons).ToList();
return Learners;
}
public bool ChemistryPassing()
{
return Learners.All(peoples => peoples.Subject == "Химия");
}

}