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 |
---|---|---|

is a power of | ||

is a power of | ||

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
```

## Comments