COCI '19 Contest 3 #5 Sob
View as PDFIt 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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