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Problems

Divisible Sum Pairs

Divisible Sum Pairs

Time limit 1 second
Memory limit 128 MiB

You are given an array of integers A = (a_0, a_1, ..., a_{n-1}) and a positive integer k. Find and print the number of pairs (i, j) where i < j and a_i + a_j is divisible by k.

Input data

The first line contains integer n~(2 \le n, k \le 100) and k. The second line contains n integers describing the values of A = (a_0, a_1, ..., a_{n-1})~(1 \le a_i \le 100).

Output data

Print the number of pairs (i, j) where i < j and a_i + a_j is divisible by k.

Examples

Input example #1
6 3
1 3 2 6 1 2
Output example #1
5