using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<Alphabet> list = new List<Alphabet>()

        {

            new Alphabet() { A = 9, B = 1 },

            new Alphabet() { A = 8, B = 2 },

            new Alphabet() { A = 7, B = 3 },

            new Alphabet() { A = 6, B = 4 },

            new Alphabet() { A = 5, B = 5 },

            new Alphabet() { A = 4, B = 6 },

            new Alphabet() { A = 3, B = 7 },

            new Alphabet() { A = 2, B = 8 },

            new Alphabet() { A = 1, B = 9 },

        };

        var ex1 = list.First(x => x.A > 4 && x.B < 4);

        Console.WriteLine($"A: {ex1.A} B: {ex1.B}");

        var ex2 = list.Where(x => x.A > 4 && x.B < 4).First();      

        Console.WriteLine($"A: {ex2.A} B: {ex2.B}");

    }

}

​

 public class Alphabet

 {

        public int A = 0; 

        public int B = 0;

// both A and B contai a single number  between 1-9

 }