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.IOException;
import java.io.UnsupportedEncodingException;
import java.util.InputMismatchException;
import java.util.HashMap;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.Collection;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
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.readInt();
    HashMap<Integer, Long> l = new HashMap<Integer, Long>();
    long res = 0L;
    for (int i = 0; i < n; i++){
      int v = f(in.readInt());
      if (l.containsKey(v))
        l.put(v, l.get(v) + 1L);
      else
        l.put(v, 1L);
    }
    for (long v : l.values()){
      res += get(v);
    }
    out.print(res);
  }

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

  public long get(long v){
    long res = 1;
    for (int i = 1; i <= v; i++)
      res *= i;
    return res / 2L;
  }

}

class InputReader {

  private InputStream stream;
  private byte[] buf = new byte[1024];
  private int curChar;
  private int numChars;

  public InputReader(InputStream stream) {
    this.stream = stream;
  }

  public int read() {
    if (numChars == -1)
      throw new InputMismatchException();
    if (curChar >= numChars) {
      curChar = 0;
      try {
        numChars = stream.read(buf);
      } catch (IOException e) {
        throw new InputMismatchException();
      }
      if (numChars <= 0)
        return -1;
    }
    return buf[curChar++];
  }

  public int readInt() {
    int c = read();
    while (isSpaceChar(c))
      c = read();
    int sgn = 1;
    if (c == '-') {
      sgn = -1;
      c = read();
    }
    int res = 0;
    do {
      if (c < '0' || c > '9')
        throw new InputMismatchException();
      res *= 10;
      res += c - '0';
      c = read();
    } while (!isSpaceChar(c));
    return res * sgn;
  }

  public static boolean isSpaceChar(int c) {
    return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  }

  }

