/** My Java solution to http://projecteuler.net/problem=13
 *
 * @author MUHAMMAD AZRI BIN JASNI @ ABDUL RANI
 * @version 29 SEPTEMBER 2012
 *
 * http://docs.oracle.com/javase/1.4.2/docs/api/java/math/BigInteger.html
 * http://www.leepoint.net/notes-java/data/numbers/10biginteger.html
 *
 * BigInteger is immutable. Therefore, you can't change sum, you need to reassign the result of the add method to sum.
 * "input.dat"
 */
import java.math.BigInteger;//BigInteger superclass
import java.io.*;//File
import java.util.*;//Scanner
public class solution13{
    //set up inFile, SIZE and array
    public static File            inFile   = new File("input.dat");//input in dat file
    public static final int SIZE = 100;//size of input (100 number of 50 digits)
    public static BigInteger [] array = new BigInteger[SIZE];//storing the input

    public static void main(String [] args)throws IOException {
        //local declaration - stream and sum
        Scanner sc = new Scanner(inFile);
        BigInteger sum = new BigInteger("0");//sum of the BigInteger array
        for (int i=0; i<SIZE; i++){
            array[i] = new BigInteger(sc.nextLine());
        }

        //testDisplay to test file input
        //testDisplay();

        //Sum Them!
        for (int i=0; i<SIZE; i++){
            sum=sum.add( (array[i]) );
        }
        //Display sum
        System.out.println("sum:");
        System.out.println(sum.toString().substring(0,10));
        //inStream.close();//close stream
        sc.close();
    }
    public static void testDisplay(){
        for (int i=0; i<SIZE; i++){
            System.out.println(array[i]);
        }
    }
}