Dima got into number sequences. Now he's got sequence a₁,a₂,...,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.

The first line contains integer n (1≤n≤10⁵). The second line contains n positive integers a₁,a₂,...,a_n (1≤a_i≤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.