import java.util.Scanner;

public class StackOfStrings {
	
	private String[] items;
	private int size;
	
	public StackOfStrings(int capacity) {
		items = new String[capacity];
		size = 0; 
	}
	
	public boolean isEmpty() {
		return (size == 0);
	}
	
	public boolean isFull() {
		return (size == items.length);
	}
	
	public void push(String s) {
		if (this.isFull()) {
			throw new RuntimeException("Stack Overflow");
		}
		items[size++] = s;
	}
	
	public String pop() {
		if (this.isEmpty()) {
			throw new RuntimeException("Stack Underflow");
		}
		return items[--size];
	}

	public static void main(String[] args) {
		System.out.println("Enter a sequence of words and/or dashes separated by spaces.");
		System.out.println("Words will be pushed to an initially empty stack with capacity 5.");
		System.out.println("Dashes will result in popping the stack and printing the result.");
		Scanner scanner = new Scanner(System.in);
		String userInputStr = scanner.nextLine();
		scanner.close();
		String[] userInputs = userInputStr.split(" ");
		StackOfStrings stack = new StackOfStrings(5);
		for (int i = 0; i < userInputs.length; i++) {
			if (userInputs[i].equals("-"))
				System.out.println(stack.pop());
			else 
				stack.push(userInputs[i]);
		}
	}

}