def countPairs(arr, k):
    # Write your code here
    results = []
    working_pair = []
    length = len(arr)

    for i in range(length - 1):
        for j in range(i+1, length):
            if (arr[i] + arr[j] == k):
                working_pair = sorted([arr[i], arr[j]])
                if(working_pair not in results):
                    results.append(working_pair)

    return len(results)