**These problems are from the atcoder DP contest, and were transferred onto DMOJ. All problem statements were made by several atcoder users. As there is no access to the test data, all data is randomly generated. If there are issues with the statement or data, please contact or on slack.**

There are rabbits, numbered .

For each , the compatibility of Rabbit and is described by an integer . Here, for each , and for each and .

Taro is dividing the rabbits into some number of groups. Here, each rabbit must belong to exactly one group. After grouping, for each and , Taro earns if Rabbit and belong to the same group.

Find Taro's maximum possible total score.

#### Constraints

- All values in input are integers.

#### Input Specification

The first line will contain the integer .

The next lines will each contain integers, .

#### Output Specification

Print Taro's maximum possible total score.

#### Sample Input 1

```
3
0 10 20
10 0 -100
20 -100 0
```

#### Sample Output 1

`20`

#### Explanation For Sample 1

The rabbits should be divided as .

#### Sample Input 2

```
2
0 -10
-10 0
```

#### Sample Output 2

`0`

#### Explanation For Sample 2

The rabbits should be divided as .

#### Sample Input 3

```
4
0 1000000000 1000000000 1000000000
1000000000 0 1000000000 1000000000
1000000000 1000000000 0 -1
1000000000 1000000000 -1 0
```

#### Sample Output 3

`4999999999`

#### Explanation For Sample 3

The rabbits should be divided as . Note that the answer may not fit into a 32-bit integer type.

#### Sample Input 4

```
16
0 5 -4 -5 -8 -4 7 2 -4 0 7 0 2 -3 7 7
5 0 8 -9 3 5 2 -7 2 -7 0 -1 -4 1 -1 9
-4 8 0 -9 8 9 3 1 4 9 6 6 -6 1 8 9
-5 -9 -9 0 -7 6 4 -1 9 -3 -5 0 1 2 -4 1
-8 3 8 -7 0 -5 -9 9 1 -9 -6 -3 -8 3 4 3
-4 5 9 6 -5 0 -6 1 -2 2 0 -5 -2 3 1 2
7 2 3 4 -9 -6 0 -2 -2 -9 -3 9 -2 9 2 -5
2 -7 1 -1 9 1 -2 0 -6 0 -6 6 4 -1 -7 8
-4 2 4 9 1 -2 -2 -6 0 8 -6 -2 -4 8 7 7
0 -7 9 -3 -9 2 -9 0 8 0 0 1 -3 3 -6 -6
7 0 6 -5 -6 0 -3 -6 -6 0 0 5 7 -1 -5 3
0 -1 6 0 -3 -5 9 6 -2 1 5 0 -2 7 -8 0
2 -4 -6 1 -8 -2 -2 4 -4 -3 7 -2 0 -9 7 1
-3 1 1 2 3 3 9 -1 8 3 -1 7 -9 0 -6 -8
7 -1 8 -4 4 1 2 -7 7 -6 -5 -8 7 -6 0 -9
7 9 9 1 3 2 -5 8 7 -6 3 0 1 -8 -9 0
```

#### Sample Output 4

`132`

## Comments

In the sentence

it should be so the values aren't counted twice.