using System;

public class Program

{

    public static void Main()

    {

        int [] numbers = new int[] {1, 3, 5, 7, 10, 12, 13};

        int length = numbers.Length;

        int LB = 0;

        int UB = length -1;

        int MP = (LB + (UB - LB)/2);

        Console.WriteLine("What number do you want to find?");

        int search = Convert.ToInt32(Console.ReadLine());

        bool found = false;

        while (found = false && LB <= UB)

        {

            if (search == MP)

            {

                found = true;

            }

            else if (numbers[MP] < search)

            {

                LB = MP + 1;

            }

            else

            {

                UB = MP - 1;

            }

        }

        if (found == true)

        {

            Console.WriteLine("Number found at {}", MP);

        }

        else

        {

            Console.WriteLine("Number not found in list");

        }

    }

}