class Solution {
     private Queue<Integer> queueFirst;
    private Solution(){
        queueFirst = new LinkedList<>();
    }

    public Solution(List<Integer> v1, List<Integer> v2) {
        queueFirst = new LinkedList<>();
        boolean toggle = true;
        int v1Index = 0;
        int v2Index = 0;
        while(!(v1Index==v1.size()) || !(v2Index==v2.size())){
            if(!(v1Index==v1.size())){
                queueFirst.add(v1.get(v1Index++));
            }
            if(!(v2Index==v2.size())){
                queueFirst.add(v2.get(v2Index++));
            }
        }
    }

    public int next() {
        if(!queueFirst.isEmpty()){
            return queueFirst.poll();
        }
        return -1;
    }

    public boolean hasNext() {
        return !queueFirst.isEmpty();
    }