Dima got into number sequences. Now he's got sequence a 1, a 2, ..., a n , 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(a i ) = f(a j ). Help him, count the number of such pairs.

输入描述:

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.

输出描述:

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.

备注:

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.