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.InputStreamReader;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.InputStream;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Scanner;
/**
 * 
 * Yerasyl Abenov 
 * 
 */
public class Main {
    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
            try (PrintWriter out = new PrintWriter(outputStream)) {
                TaskB solver = new TaskB();
                solver.solve(1, in, out);
            }
    }
}
class TaskB {
    public void solve(int testNumber, InputReader in, PrintWriter out) throws FileNotFoundException, IOException {
        int n = in.nextInt();
        int a[] = new int[100111];
        for (int i = 0; i < n; ++i) {
            int x = in.nextInt();
            int cnt = 0;
            while (x > 0) {
                if (x%2 != 0) cnt++;
                x /= 2;
            }
            a[cnt]++;
        }
        long ans = 0;
        for (int i = 0; i < 100; ++i) {
            ans += (a[i]*(a[i] - 1))/2;
        }
        out.println(ans);
    }
}
class InputReader {
    private final BufferedReader reader;
    private StringTokenizer tokenizer;
    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream));
        tokenizer = null;
    }
      
      
    public String nextLine() {
        try {
            return reader.readLine();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
      
    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(nextLine());
        }
        return tokenizer.nextToken();
    }
      
    public int nextInt() {
        return Integer.parseInt(next());
    }
    public long nextLong() {
        return Long.valueOf(next());
    }
    public BigInteger nextBigInteger() {
        return new BigInteger(next());
    }
     
}