## Divisible Sum Pairs

by wanbo

You are given an array of integers, , and a positive integer, . Find and print the number of pairs where and + is divisible by .

**Input Format**

The first line contains space-separated integers, and .

The second line contains space-separated integers describing the values of .

**Constraints**

**Output Format**

Print the number of pairs where and + is evenly divisible by .

**Sample Input**

```
6 3
1 3 2 6 1 2
```

**Sample Output**

```
5
```

**Explanation**

Here are the valid pairs when :