import java.io.*;
import java.util.Scanner;

public class Solution {
    public static void main(String[] args) throws Exception {
        int a=0;
        int sum=0;
        Scanner aa=new Scanner(System.in);


        while (a!=-1) {
             a=aa.nextInt();
            sum+=a; }
            System.out.println(sum);

        }
    }