O(1) Time complexity to obtain the maximum value of the queue

class MaxQueue {
    
    
    LinkedList<Integer> deque1,deque2;

    public MaxQueue() {
    
    
        deque1=new LinkedList<>();
        deque2=new LinkedList<>();
    }
    
    public int max_value() {
    
    
        if(deque2.isEmpty()) return -1;
        else return deque2.getFirst();
    }
    
    public void push_back(int value) {
    
    
        
        while(!deque2.isEmpty()&&value>deque2.getLast()){
    
    
            deque2.removeLast();
        }
        deque1.addLast(value);
        deque2.addLast(value);

    }
    
    public int pop_front() {
    
    
        if(deque1.isEmpty()) return -1;
        if((int)deque1.getFirst()==deque2.getFirst())  deque2.removeFirst();
        return deque1.removeFirst();
    }
}