using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<Teacher> teacher = new List<Teacher>();

teacher.Add(new Teacher(1, "Teacher A", 4, 2000));

teacher.Add(new Teacher(2, "Teacher B", 3, 3000));

teacher.Add(new Teacher(3, "Teacher C", 5, 5000));

teacher.Add(new Teacher(4, "Teacher D", 3, 4000));

teacher.Add(new Teacher(5, "Teacher E", 3, 7000));

        var teachArr = teacher.ToArray();

        var threeYearTeachArr = teacher.Where(t => t.year == 3).OrderByDescending(t => t.salary).ToArray();

        for( int i = 0, threes = 0; i < teachArr.Length && threes < threeYearTeachArr.Length; i++ )

        {

            if( teachArr[i].year == 3 ) teachArr[i] = threeYearTeachArr[threes++];

        }

        foreach( var t in teachArr )

        {

            Console.WriteLine($"{t.id} {t.name} | {t.year} | {t.salary}");

        }

    }

}

​

class Teacher

{

        public int id { get; set; }

        public string name { get; set; }

        public int year { get; set; }

        public double salary { get; set; }

​

        public Teacher()

        {

        }

​

        public Teacher(int id, string name, int year, double salary)

        {

            this.id = id;

            this.name = name;

            this.year = year;

            this.salary = salary;

        }

}