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 Sunits789
 */
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 n=in.nextInt();
        int arr[]=new int[n];
        in.getArray(arr);
        int arr2[]=new int[n];
        for(int i=0;i<n;i++){
            arr2[i]=f(arr[i]);
        }
        int c[]=new int[200];
        Arrays.fill(c,0);
        for(int i=0;i<n;i++){
            c[arr2[i]]++;
        }
        long ans=0;
        for(int i=0;i<200;i++){
            if(c[i]>0){
                //System.out.println(c[i]);
                ans+=(long)((long)c[i]*(long)(c[i]-1))/(long)2;
            }
        }
        out.println(ans);
    }

    private int f(int i){
        if(i==0){
            return 0;
        }
        if(i%2==0){
            return f(i/2);
        }
        return f(i/2)+1;
    }
}

class InputReader{
    private BufferedReader reader;
    private StringTokenizer tokenizer;

    public InputReader(InputStream stream){
        reader = new BufferedReader(new InputStreamReader(stream));
        tokenizer = null;
    }
    public String next(){
        while (tokenizer == null||!tokenizer.hasMoreTokens()){
            try{
                tokenizer = new StringTokenizer(reader.readLine());
            }
            catch (IOException e){
                throw new RuntimeException(e);
            }

            catch (NullPointerException e){
                throw new UnknownError();
            }
        }
        return tokenizer.nextToken();
    }

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

    public void getArray(int arr[]){
        for(int i=0;i<arr.length;i++){
            arr[i]=nextInt();
        }
    }

    }

