import java.util.*;

import java.io.*;





/* ====================================================================== */

/** This class converts decimals and binary

 *

 */

class BinaryToDecimal {





	public static void main( String [] args ){



		getBinaryNumberFromUser(); //asks the user to type a binary number

		int Sum=0;

		int Exponent=0;

		

		

		

		while( notDone() ){

			int binary_digit = getNextDigit(); //moves right to left

			int getNextDigit;

			int digit=binary_digit;

			int decimal_number= digit * (int)Math.pow(2, Exponent);

			Sum= Sum + (int) decimal_number;		

			

			Exponent++;

			System.out.println("sum =" + Sum);

		}



	

	} //end main





   	/* ===================================================================== */

	/** This method is used to read in a single binary number.  In order for

	 *  it to work properly, the user must enter 1s and 0s.

	 *

	 */

    public static BinaryNumber getBinaryNumberFromUser(){



		try{

			System.out.println("Type in a binary number:");

			BufferedReader input = new BufferedReader(new InputStreamReader(System.in));

			String message = input.readLine();



			input.close();



			binary_number = new BinaryNumber(message);



		}catch(IOException e){System.out.println("Unable to read a number");}



		//this only happens if there was an exception

		return new BinaryNumber("");



	} //method: read





    public static boolean notDone(){ return binary_number.notDone(); }

    

    public static int getNextDigit(){ return binary_number.getNextNum(); }



	private static BinaryNumber binary_number;



	private static class BinaryNumber{



		private String number;

		private int index;



		public BinaryNumber(String number){

			this.number = number;

			index = number.length();

		}





		public int getNextNum(){

			int n = Integer.parseInt(number.substring(index-1,index));

			index--;

			return n;

		}



		public boolean notDone(){

			return (index > 0);

		}



	}



} //class: BinaryToDecimal