using System;

using System.Collections.Generic;

public class Program

{

    public static int search(int[] a,int target)

    {

    int min=0;

        int max=(a.Length)-1;

        while(min<=max)

        {

        int mid=(min+max)/2;

            if(a[mid]<target)

            {

            min=mid+1;

            }

            else if(a[mid]>target)

            {

            max=mid-1;

            }

            else

            {

            return mid;

            }

        }

        return -1;

    }

    public static void Main()

    {

        int[] f={1,2,3};

        int res=search(f,2);

        Console.WriteLine(res);

    }

}