It was a dark and dreary Christmas Eve when our hero pondered, weak and weary, over a quaint and curious COCI task. When he nodded, nearly napping, suddenly he heard a tapping, tapping and a mighty roar. A giant reindeer broke through his chamber door, merely this and nothing more. While our hero's heart slightly fluttered, the beast simply uttered: "I won't leave until you solve this problem".
In the problem, you were given two integers and
and you were supposed to
perfectly match the numbers from sets
and
into
pairs, such that for the matched numbers
and
it holds
, where
denotes a bitwise AND operation.
Input
The first line contains two integers and
from the task description.
Output
You should output lines and in each line you should output two integers
and
, where
belongs to
set
and
belongs to set
. Numbers in each line should correspond to one of the matched pairs from
the task description.
It is possible to prove that the solution always exists.
Scoring
Subtask | Score | Constraints |
---|---|---|
No additional constraints. |
Sample Input 1
1 3
Sample Output 1
0 3
Sample Input 2
3 5
Sample Output 2
0 5
1 7
2 6
Sample Input 3
5 10
Sample Output 3
0 12
1 13
2 10
3 11
4 14
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