import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class SumAdjacentNumbers {


    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        List<Double> number = Arrays.stream(scanner.nextLine().split(" ")).map(Double::parseDouble).collect(Collectors.toList());

        int i = 0;
        while (i < number.size() - 1) {
            double currentNumber = number.get(i);
            double nextNumber = number.get(i + 1);
            if (currentNumber == nextNumber) {
                double sum = currentNumber + nextNumber;
                number.set(i, sum);
                number.remove(i + 1);
                i = 0;
            } else {
                i++;
            }

        }


        for (Double aDouble : number) {
            System.out.println(number + " ");

        }


    }
}