Description: Dima got into number sequences. Now he's got sequence a1, a2, ..., an, consisting of n positive integers. Also, Dima has got a function f(x), which can be defined with the following recurrence: - f(0) = 0; - f(2·x) = f(x); - f(2·x + 1) = f(x) + 1. Dima wonders, how many pairs of indexes (i, j) (1 ≤ i < j ≤ n) are there, such that f(ai) = f(aj). Help him, count the number of such pairs. Input Format: The first line contains integer n (1 ≤ n ≤ 105). The second line contains n positive integers a1, a2, ..., an (1 ≤ ai ≤ 109). The numbers in the lines are separated by single spaces. Output Format: In a single line print the answer to the problem. Please, don't use the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64d specifier. Note: In the first sample any pair (i, j) will do, so the answer is 3. In the second sample only pair (1, 2) will do.