import java.util.Scanner;

class Binary
{
 int A[];
 int n,l,u;
 
 public Binary(int nn)
 {
     n=nn;
     A=new int[n];
     l=0;
     u=n-1;
    }
    
   public void readdata()
   {
       Scanner in=new Scanner(System.in);
       System.out.println("Enter the elments of the array in ascending order: ");
       
       for(int i=0;i<n;i++)
       {
           A[i]=in.nextInt();
        }
    }
    
    public int binarysearch(int v)
    {
      if(l>u)
      return -1;
      
      else
      {
        int mid=(l+u)/2;
        
        if(A[mid]==v)
        return mid+1;
        
        else if(v<A[mid])
        {
          u=mid-1;
          return binarysearch(v);
        }
        
        else 
        {
         l=mid+1;
         return binarysearch(v);
        }
        
        }   
    }
}