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.Scanner;
import java.util.StringTokenizer;


public class Classy {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int N = sc.nextInt();
		long[] array = new long[100000];
		for(int a=0;a<N;a++){
			array[Long.bitCount(sc.nextLong())]++;
		}
		long ans = 0;
		
		for(int a=0;a<array.length;a++){
			ans+=(array[a]*(array[a]-1))/2L;
		}
		
		out.println(ans);
		out.close();
	}


	static class FastScanner {
		BufferedReader br;
		StringTokenizer st;
		
		public FastScanner(InputStream in) throws Exception{
			br = new BufferedReader(new InputStreamReader(in));
			st = new StringTokenizer(br.readLine().trim());
		}
		public int numTokens() throws Exception {
			if(!st.hasMoreTokens()){
				st = new StringTokenizer(br.readLine().trim());
				return numTokens();
			}
			return st.countTokens();
		}
		public boolean hasNext() throws Exception{
			if(!st.hasMoreTokens()){
				st = new StringTokenizer(br.readLine().trim());
				return hasNext();
			}
			return true;
		}
		public String next() throws Exception {
			if(!st.hasMoreTokens()){
				st = new StringTokenizer(br.readLine().trim());
				return next();
			}
			return st.nextToken();
		}
		public double nextDouble() throws Exception{
			return Double.parseDouble(next());
		}
		public float nextFloat() throws Exception{
			return Float.parseFloat(next());
		}
		public long nextLong() throws Exception{
			return Long.parseLong(next());
		}
		public int nextInt() throws Exception{
			return Integer.parseInt(next());
		}
		public String nextLine() throws Exception{
			return br.readLine();
		}
	}


}
