学步园

import java.io.*;
import java.util.*;
import java.math.*;
public class Main
{
public static void main(String[] args)
    {
        String s;
        BigInteger a,b,c;
        Scanner sc=new Scanner(System.in);
        Scanner cin=new Scanner(System.in);
        b=BigInteger.valueOf(0);
while(cin.hasNext())
        {
            a=cin.nextBigInteger();
            s=a.toString();
if(s.equals("0")) break;
            b=b.add(a);
        }
        System.out.println(b);
    }
}