import java.math.BigInteger;
import java.util.Scanner;

/**
 *
 * @author FangZhiyang
 */
public class Main
{
	public static void main(String[] args)
	{
		Scanner cin = new Scanner(System.in);
		String input = cin.nextLine();
		BigInteger result = new BigInteger("0");
		while (!input.equals("0"))
		{
			result = result.add(new BigInteger(input));
			input = cin.nextLine();
		}
		System.out.println(result);
	}
}