using System.Collections.Generic;
using System.Diagnostics;
public int Id { get; set; }
public int Age { get; set; }
public Person(int id, int age)
public static void Main()
List<Person> pers = new List<Person>();
pers.Add(new Person(1, 20));
pers.Add(new Person(2, 15));
pers.Add(new Person(3, 10));
pers.Add(new Person(4, 15));
Person person = pers.FirstOrDefault(imp => imp.Id == refId2ImpUni && imp.Age == refId3ImpLie);
person = pers.FirstOrDefault(imp => imp.Id == refId2ImpUni || imp.Age == refId3ImpLie) ?? pers.FirstOrDefault();
Console.WriteLine(person.Id);