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.util.*;
import java.util.StringTokenizer;
import java.math.BigInteger;

public class SolutionB {
   BufferedReader in;
   StringTokenizer str;
   PrintWriter out;
   String SK;
   long ff[];
   String next() throws IOException {
      while ((str == null) || (!str.hasMoreTokens())) {
         SK = in.readLine();
         if (SK == null)
              return null;
         str = new StringTokenizer(SK);
      }
      return str.nextToken();
   }
   int nextInt() throws IOException {
      return Integer.parseInt(next());
   }
   double nextDouble() throws IOException {
      return Double.parseDouble(next());
   }
   long nextLong() throws IOException {
      return Long.parseLong(next());
   }
   void run() throws IOException {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        //in = new BufferedReader(new FileReader("input.txt"));
        //out = new PrintWriter("output.txt");
        solve();
        out.close();

   }
   public static void main(String[] args) throws IOException {
      new SolutionB().run();
   }

   void solve() throws IOException {
       int n=nextInt();
       int num[]=new int[n];
       for(int i=0;i<n;i++){
            num[i]=nextInt();
       }
       ff=new long[100000];
       Arrays.sort(num);
       for(int i=0;i<n;i++){
            ff[(int)f(num[i])]++;
       }
       long count=0;
       for(int i=1;i<ff.length;i++){
           if(ff[i]>0) 
           count+=(ff[i]*(ff[i]-1))/2;
       }
        out.println(count);


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

}

