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

public class Shoot {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        String[] split = scanner.nextLine().split("\\+s"){
            List<Integer> target = new ArrayList<>();
            List<String> results = new ArrayList<>();

            for (String s: split) {
                String command = scanner.nextLine();

                while (!command.equals("End")){

                    int indexShoots = Integer.parseInt(command){
                        if (indexShoots >= 0 && indexShoots < target.size()){

                            int valueOfTheTarget = target.get(indexShoots);

                            for (int i = 0; i <target.size() ; i++) {
                                int currents = target.get(1);


                                if (i == indexShoots){
                                    continue;
                                } else if (currents == -1){
                                    continue;
                                }
                                if (currents <= valueOfTheTarget){
                                    currents += valueOfTheTarget;


                                    target.set(i, currents);
                                } else {
                                    currents -= valueOfTheTarget;
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}