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

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

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.

Examples

Input

3
1 2 4


Output

3


Input

3
5 3 1


Output

1

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.
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author vadimmm
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskB solver = new TaskB();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskB {

    public void solve(int testNumber, InputReader in, PrintWriter out) {
        int counter = in.nextInt();
        if (counter < 2) {
            out.println(0);
            return;
        }
        int[] numbers = new int[counter];
        int number;
        for (int i = 0; i < counter; ++i) {
            number = in.nextInt();
            while (number > 0) {
                if (number % 2 == 0)
                    number /= 2;
                else {
                    --number;
                    ++numbers[i];
                }
            }
        }
        Arrays.sort(numbers);
        int current = 1;
        long answer = 0;
        for (int i = 1; i < counter; ++i)
            if (numbers[i] == numbers[i - 1])
                ++current;
            else {
                answer += 1L * current * (current - 1) / 2;
                current = 1;
            }
        if (numbers[counter - 1] == numbers[counter - 2])
            answer += 1L * current * (current - 1) / 2;
        out.println(answer);
    }

}

class InputReader {

    private static BufferedReader bufferedReader;
    private static StringTokenizer stringTokenizer;

    public InputReader(InputStream inputStream) {
        bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        stringTokenizer = null;
    }

    public String next() {
        while(stringTokenizer == null || !stringTokenizer.hasMoreTokens()) {
            try {
                stringTokenizer = new StringTokenizer(bufferedReader.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return stringTokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    }

