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.
// 10 monthes remaining for red =D
import java.io.*;
import java.util.*;

/**
 * @author icemore
 */
public class Main {

    int f(int num)
    {
        if(num==0)return 0;
        return f(num/2) + num%2;
    }
    
    void solve() throws IOException
    {        
        int n = nextInt();
        
        Map<Integer, Integer> map = new HashMap<>();
        
        for (int i = 0; i < n; i++) {
            int k=f(nextInt());
            int cur= map.containsKey(k) ? map.get(k) : 0;
            map.put(k, cur+1);
        }
        
        long ans=0;
        for (Iterator<Map.Entry<Integer, Integer>> it = map.entrySet().iterator(); it.hasNext();) {
            long cur = it.next().getValue();
            
            ans+=cur*(cur-1)/2;
        }
        
        out.print(ans);
    }
    
    // <editor-fold defaultstate="collapsed" desc="Template">
    
    String nextToken() throws IOException
    {
        in.nextToken();
        return in.sval;
    }
    
    double nextDouble() throws IOException
    {
        in.nextToken();
        return in.nval;
    }
    
    long nextLong() throws IOException
    {
        in.nextToken();
        return (long)in.nval;
    }
    
    int nextInt() throws IOException
    {
        in.nextToken();
        return (int)in.nval;
    }
    
    void run() throws IOException
    {
        boolean onlineJudge = System.getProperty("ONLINE_JUDGE")!=null;
        Reader reader = onlineJudge ? new InputStreamReader(System.in) : new FileReader("input.txt");
        Writer writer = onlineJudge ? new OutputStreamWriter(System.out) : new FileWriter("output.txt");
        
        in = new StreamTokenizer(new BufferedReader(reader));
        out = new PrintWriter(writer);
        solve();
        out.close();
    }
    
    public static void main(String[] args) throws IOException {
        new Main().run();
    }
    
    StreamTokenizer in;
    PrintWriter out;
    // </editor-fold>
}
