using System;

public class Program

{

    public static void Main()

    {

        int[] intArray = new int[]{1,2,3,4,5,6,7,8};    

        Console.WriteLine(BinarySearch(intArray ,2));

    }

    public static int BinarySearch(int[] intArray, int value){

        int high = intArray.Length -1;

        int low =0;

        int midpoint = 0;

        while( low<= high)

        {

            midpoint = low + (high-low)/2;

            if (value == intArray[midpoint]){

            return midpoint;

            }

            else if(value < intArray[midpoint]){

                high = midpoint - 1;

            }

            else{

                low = midpoint + 1;

            }

        }

        return -1;

    }

}