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

/**
* Built using CHelper plug-in
* Actual solution is at the top
* @author Togrul Gasimov
*/
public class Main {
  public static void main(String[] args) {
      InputStream inputStream = System.in;
      OutputStream outputStream = System.out;
      FastScanner scan = new FastScanner(inputStream);
      FastPrinter out = new FastPrinter(outputStream);
      TaskA solver = new TaskA();
      solver.solve(1, scan, out);
      out.close();
  }
}
 // salam
class TaskA {
  
  static int fanar(int n){
	  if(n == 0) return 0;
	  else if( n % 2 == 1) return fanar((n - 1) / 2) + 1;
	  else return fanar(n / 2);
  }
  public void solve(int testNumber, FastScanner scan, FastPrinter out) {
      Scanner in = new Scanner(System.in);
      
      int n, k, ans = 0;
     
      n = in.nextInt();
      
     int[] a = scan.readIntArray(n); 
      int[] x = new int[1000000];
     for(int i = 1; i <= n - 1; i++){
    	 k = fanar(a[i]);
    	 ans += x[k];
    	 x[k]++;
     }
     out.println(ans);
   
  }
}

class FastScanner extends BufferedReader {

  public FastScanner(InputStream is) {
      super(new InputStreamReader(is));
  }

  public int read() {
      try {
          int ret = super.read();
//            if (isEOF && ret < 0) {
//                throw new InputMismatchException();
//            }
//            isEOF = ret == -1;
          return ret;
      } catch (IOException e) {
          throw new InputMismatchException();
      }
  }

  static boolean isWhiteSpace(int c) {
      return c >= 0 && c <= 32;
  }

  public int nextInt() {
      int c = read();
      while (isWhiteSpace(c)) {
          c = read();
      }
      int sgn = 1;
      if (c == '-') {
          sgn = -1;
          c = read();
      }
      int ret = 0;
      while (c >= 0 && !isWhiteSpace(c)) {
          if (c < '0' || c > '9') {
              throw new NumberFormatException("digit expected " + (char) c
                      + " found");
          }
          ret = ret * 10 + c - '0';
          c = read();
      }
      return ret * sgn;
  }

  public String readLine() {
      try {
          return super.readLine();
      } catch (IOException e) {
          return null;
      }
  }

  public int[] readIntArray(int n) {
      int[] ret = new int[n + 1];
      for (int i = 1; i <= n; i++) {
          ret[i] = nextInt();
      }
      return ret;
  }

  }

class FastPrinter extends PrintWriter {

  public FastPrinter(OutputStream out) {
      super(out);
  }

  public FastPrinter(Writer out) {
      super(out);
  }


}