// @Title: 图书整理 II (图书整理 II)
// @Author: qisiii
// @Date: 2022-02-19 20:13:16
// @Runtime: 61 ms
// @Memory: 47.5 MB
// @comment: 
// @flag: 
class CQueue {

  private Stack<Integer> pushStack=new Stack();
    private Stack<Integer> popStack=new Stack();
    public CQueue() {

    }

    public void appendTail(int value) {
        pushStack.push(Integer.valueOf(value));
    }

    public int deleteHead() {
        if (popStack.isEmpty()){
            while (!pushStack.isEmpty()){
                Integer pop = pushStack.pop();
                popStack.push(pop);
            }
        }
       if (popStack.isEmpty()){
            return -1;
        }
        return popStack.pop();
    }
}

/**
 * Your CQueue object will be instantiated and called as such:
 * CQueue obj = new CQueue();
 * obj.appendTail(value);
 * int param_2 = obj.deleteHead();
 */