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

public class Main {
    public static void main(String args[]) {
        Scanner cin = new Scanner(new BufferedInputStream(System.in));

        BigInteger a;
        BigInteger b = new BigInteger("0");
        BigInteger c = new BigInteger("0");
        while(cin.hasNextBigInteger()) {
            a = cin.nextBigInteger();
            if(a.compareTo(c) == 0) break;

            b = b.add(a);
        }
        System.out.println(b);
    }
}