class ZigzagIterator(object):

```
def __init__(self, v1, v2):
"""
Initialize your data structure here.
:type v1: List[int]
:type v2: List[int]
"""
self.queue=[_ for _ in (v1,v2) if _]
def next(self):
"""
:rtype: int
"""
v=self.queue.pop(0)
ret=v.pop(0)
if v: self.queue.append(v)
return ret
def hasNext(self):
"""
:rtype: bool
"""
if self.queue: return True
return False
```