// Repeatedly read a sequence of "add <double>", "get" and "status"
// commands from standard input.  Command "add" adds its operand at 
// the end of a FIFO queue; command "get" removes and prints the double 
// at the front of the queue; command "status" prints the size of
// the queue and the sum of the doubles in the queue.

// Class Queue maintains a FIFO queue of doubles.
class Queue {
    List elements;
    Double elementSum;

    // Constructor.
    Queue () {
        elements = new List();
        elementSum = 0;
    }

    // Adds double at end of queue.
    void add (Double element) {
        elements.add(element);
        elementSum = elementSum + element;
    }

    // Returns double at front of queue and removes it.
    Double get () {
        Double element;
        element = [Double]elements.get(0);
        elements.remove(0);
        elementSum = elementSum - element;
        return element;
    }
    
    // Returns sum of current queue elements.
    Double sum() { return elementSum; }
        
    // Returns number of elements in queue.
    Integer size() { return elements.size(); }
}

// Class Main contains the main function main().
class Main {
    // Repeatedly read and execute commands.
    void main () {
        Queue queue;
        Double double;
        
        queue = new Queue();
        while (true) {
            String command;
            command = system.readString();
            if (command.equals("add")) {
                double = system.readDouble();
                queue.add(double);
            } elseif (command.equals("get")) {
                double = queue.get();
                system.println(double);
            } elseif (command.equals("status")) {
                system.print("Length: "); 
                system.println(queue.size());
                system.print("Sum: ");
                system.print(queue.sum());
            } else {
                system.print("Error: Invalid command: ");
                system.println(command);
            }
        }
    }
}