using System;

public class Program

{

    public static void Main()

    {

        //Console.WriteLine("Hello World");

        int[] a = {1,2,3,4,5,6,7,8,9,10};

        if(BinarySearchDisplay(a, 0))

           Console.WriteLine("Found");

        else

           Console.WriteLine("Not Found");

    }

 public static bool BinarySearchDisplay(int[] arr, int key) {

   int minNum = 0;

   int maxNum = arr.Length - 1;

    if(key > arr[maxNum] || key < arr[minNum])

        return false;

   while (minNum <=maxNum) {

      int mid = (minNum + maxNum) / 2;

      if (key == arr[mid]) {

         return true;

      } else if (key < arr[mid]) {

         maxNum = mid - 1;

      }else {

         minNum = mid + 1;

      }

   }

   return false;

}

}