Max has just started grade , and he is in his math class, learning equations of lines!

Max defines the slope-intercept form of a line as the equation of the line in the form . Max is given lines in slope-intercept form, each with a **distinct** *and* . Max wants to see, at some integer , the maximum possible value out of all the lines. He wants to test **all** integer values of in the range , and wants the sum of these values.

Not knowing how to do it, he has asked you to do it for him! Help him!

#### Input Specification

The first line will contain the integer , the number of lines.

The next lines will each contain two integers, . It is guaranteed both and are distinct.

#### Output Specification

On the first line, output the sum of the maximum possible values for every integer in the range . Note that 64-bit integers may be required to pass.

#### Subtasks

##### Subtask 1 [40%]

##### Subtask 2 [60%]

No further constraints.

#### Sample Input 1

```
3
4 2
-4 -6
0 -2
```

#### Sample Output 1

`20000400000`

#### Sample Input 2

```
2
-1 1000
1 -1000
```

#### Sample Output 2

`4901049000`

## Comments