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 \cdot x)=f(x); f(2 \cdot x+1)=f(x)+1.
Dima wonders, how many pairs of indexes (i,j) (1 \le i \lt j \le n) are there, such that f(ai)=f(aj). Help him, count the number of such pairs.

The first line contains integer n (1 \le n \le 105). The second line contains n positive integers a1,a2,...,an (1 \le ai \le 109).

The numbers in the lines are separated by single spaces.

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.

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.