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.*;
import java.math.*;
import java.text.*;
import java.util.*;

//Codeforces
public class MainCodeforces1 {
	private static MyScanner in;
	private static PrintStream out;

	public static void main(String[] args) throws IOException {
		// helpers for input/output
		boolean LOCAL_TEST = false;// change to false before submitting
		out = System.out;
		if (LOCAL_TEST) {
			in = new MyScanner("E:\\zin2.txt");
		}
		else {
			boolean usingFileForIO = false;
			if (usingFileForIO) {
				// using input.txt and output.txt as I/O
				in = new MyScanner("input.txt");
				out = new PrintStream("output.txt");
			}
			else {
				in = new MyScanner();
				out = System.out;
			}
		}

		solve();
	}

	private static void solve() throws IOException
	{
		int n = in.nextInt();
		long[] a = new long[n];
		for (int i = 0; i < n; i++) {
			a[i] = in.nextLong();
		}

		long[] fa = new long[n];
		for (int i = 0; i < n; i++) {
			fa[i] = f(a[i]);
		}
		Arrays.sort(fa);

		long pairs = 0;
		int cnt = 1;
		for (int i = 1; i < n; i++) {
			if (fa[i] == fa[i - 1]) {
				cnt++;
			}
			else {
				if (cnt > 1) {
					long newPairs = fact(cnt) / 2;
					pairs += newPairs;
				}
				cnt = 1;
			}
		}
		if (cnt > 1) {
			long newPairs = fact(cnt) / 2;
			pairs += newPairs;
		}

		out.println(pairs);
	}

	static long fact(long x)
	{
		long z = 1;
		for (long i = 1; i <= x; i++) {
			z = z * i;
		}
		return z;
	}

	static long f(long x)
	{
		if (x == 0)
			return 0;
		else if (x % 2 == 0)
			return f(x / 2);
		else
			return f(x / 2) + 1;
	}

	// =====================================
	static class MyScanner {
		Scanner inp = null;

		public MyScanner() throws IOException
		{
			inp = new Scanner(System.in);
		}

		public MyScanner(String inputFile) throws IOException {
			inp = new Scanner(new FileInputStream(inputFile));
		}

		public int nextInt() throws IOException {
			return inp.nextInt();
		}

		public long nextLong() throws IOException {
			return inp.nextLong();
		}

		public double nextDouble() throws IOException {
			return inp.nextDouble();
		}

		public String nextString() throws IOException {
			return inp.next();
		}

	}

}