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.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class Test {
	public static long fact(int i){
		if(i == 0) return 1;
		if(i % 2 == 0){
			long f = fact(i / 2);
			return f * f;
		} else {
			return fact(i - 1) * i;
		}
	}
	public static int calc(int i){
		if(i == 0) return 0;
		if(i % 2 == 1){
			return calc((i - 1)/2) + 1;
		} else {
			return calc(i / 2);
		}
	}
	public static void main(String[] argv) {
		FastScanner scan = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int n = scan.nextInt();
		int arr[] = new int[n+1];
		Map<Integer, Integer> m = new HashMap<Integer, Integer>();
		for(int i = 0; i < n; ++i){
			arr[i] = scan.nextInt();
			int c = calc(arr[i]);
			if(m.containsKey(c)) m.put(c, m.get(c) + 1);
			else m.put(c, 1);
		}
		long ret = 0;
		for(Integer k : m.keySet()){
			long c = m.get(k);
			ret += (c * (c - 1)/2);
		}
		out.println(ret);
		out.close();
	}

	static class FastScanner {
		BufferedReader br;
		StringTokenizer st;

		FastScanner(InputStream is) {
			try {
				br = new BufferedReader(new InputStreamReader(is));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		String next() {
			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					return null;
				}
			}
			return st.nextToken();
		}

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

		long nextLong() {
			return Long.parseLong(next());
		}

		double nextDouble() {
			return Double.valueOf(next());
		}
	}
}