Roger has taken tests in preparation for CCO. On each test, there were a total of marks available and Roger got marks. Roger's final score is . Roger's test percentages are all distinct.

Roger's teacher decides that, for some value of , Roger's lowest percentages will be dropped in evaluating his final score. Roger discovers that it may be possible to select a different set of tests to drop which will result in a strictly higher score. Compute all such that this is the case.

#### Constraints

#### Input Specification

The first line will contain an integer .

Each of the next lines contains two integers, and .

#### Output Specification

Output lines. On the first line, output . On each of the next lines, in ascending order, print the values of for which Roger can do better than his teacher in maximizing his score. All valid values of must be generated.

#### Sample Input

```
5
1 2
5 9
3 8
4 10
1 3
```

#### Sample Output

```
2
1
2
```

## Comments