##### Short Problem Definition:

You are given an array of n integers and a positive integer, k. Find and print the number of (i,j) pairs where i < j and ai + aj is evenly divisible by k.

##### Link

##### Complexity:

time complexity is O(N^2)

space complexity is O(1)

##### Execution:

Brute force search.

##### Solution:

n,k = raw_input().strip().split(' ') n,k = [int(n),int(k)] a = map(int,raw_input().strip().split(' ')) count=0 for i in xrange(len(a)): for j in xrange(i+1,len(a)): if (a[i]+a[j]) % k == 0: count+=1 print count

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