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.math.*;
import java.util.*;

/**
* 
* @author Togrul Gasimov (ttogrul30@gmail.com)
*         Created on 13.09.2013
*/

public class Main {
public static void main(String[] args) /*throws FileNotFoundException*/ { 
    InputStream inputStream = System.in;
    OutputStream outputStream = System.out;
    FastScanner in = new FastScanner(inputStream);
    FastPrinter out = new FastPrinter(outputStream);
    TaskA solver = new TaskA();
    solver.solve(1, in, out);
    out.close();
}
}

class TaskA{
  static int f(int n){
	  int ret = 0;
	  while(n != 0){
		  if(n % 2 == 1)ret++;
		  n /= 2;
	  }
	  return ret;
  }
  static long k(long n){
	  long h = 1;
	  if(n == 1 || n == 0)return 0;
	  for(long i = n; i >= 3; i--){
		  h *= i;
	  }
	  
	  return h;
  }
public void solve(int testNumber, FastScanner scan, FastPrinter out) /*throws FileNotFoundException*/ {
    //Scanner sscan = new Scanner(new File("input.txt"));
    //PrintStream oout = new PrintStream(new File("output.txt"));
	int n = scan.nextInt(), ans = 0;
	int[] a = new int[1000001], d = new int[1000001];
	for(int i = 1; i <= n; i++){
		a[i] = scan.nextInt();
		ans += d[f(a[i])]++;
	}
	out.println(ans);
    //sscan.close();
    //oout.close();
}
}

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

public int read() {
    try{
        int ret = super.read();
        return ret;
    }catch(Exception e){
        throw new InputMismatchException();
    }
}

public String next() {
    StringBuilder sb = new StringBuilder();
    int c = read();
    while (isWhiteSpace(c)) {
        c = read();
    }
    if (c < 0) {
        return null;
    }
    while (c >= 0 && !isWhiteSpace(c)) {
        sb.appendCodePoint(c);
        c = read();
    }
    return sb.toString();
}

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 long nextLong() {
    return Long.parseLong(next());
}

public double nextDouble() {
    return Double.parseDouble(next());
}

public BigInteger nextBigInteger() {
    return new BigInteger(next());
}

public BigDecimal nextBigDecimal(){
    return new BigDecimal(next());
}

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

class FastPrinter extends PrintWriter {

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