public class Solution {
    // Write your code here.
     Stack<Character> stack = new Stack<>();
    Queue<Character> queue = new LinkedList<>();
    public void pushCharacter(char c)
    {
        stack.push(c);
    }
    public void enqueueCharacter(char c)
    {
        queue.add(c);
    }
    public char popCharacter()
    {
        return stack.pop();
    }
    public char dequeueCharacter()
    {
        return queue.remove();
    }