3 10

4
6
8
10

class EvenIterator:
    def __init__(self, s, e):
        self.current=s if s%2==0 else s+1
        self.end=e
    def __iter__(self): return self
    def __next__(self):
        if self.current>self.end: raise StopIteration
        val=self.current; self.current+=2; return val
s,e=map(int,input().split())
for n in EvenIterator(s,e):
    print(n)