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.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.StringTokenizer;
import static java.lang.Math.*;
import static java.lang.Integer.*;
import static java.lang.Long.*;
import static java.lang.String.*;
import static java.lang.Character.*;

@SuppressWarnings("unused")
public class round167B {

    static BufferedReader br = new BufferedReader(new InputStreamReader(
            System.in));
    static StringTokenizer st = new StringTokenizer("");

    static int nextInt() throws Exception {
        return Integer.parseInt(next());
    }

    static String next() throws Exception {
        while (true) {
            if (st.hasMoreTokens()) {
                return st.nextToken();
            }
            String s = br.readLine();
            if (s == null) {
                return null;
            }
            st = new StringTokenizer(s);
        }
    }
    
    public static boolean allZero(int [] seq){
        for(int i = 0 ; i < seq.length ; ++i)
            if(seq[i] != 0)
                return false;
        return true;
    }
    
    static HashMap<Integer, Integer> ind = new HashMap<Integer, Integer>();
    static int dp [];
    public static int f(int x){
        if(x == 0)
            return 0;
        Integer idx = ind.get(x);
        if(idx == null){
            idx = ind.size();
            ind.put(x, idx);
        }
        if(dp[idx] != -1)
            return dp[idx];
        return dp[idx] = x % 2 == 0 ? f(x / 2) : f(x / 2) + 1;
            
    }
    
    public static void main(String[] args) throws Exception {
        PrintWriter out = new PrintWriter(System.out);
        int n = nextInt();
        int[] seq = new int[n];
        for (int i = 0; i < n; ++i)
            seq[i] = nextInt();
        if(allZero(seq)){
            System.out.println((n * (n - 1)) / 2);
            return;
        }
        dp = new int [10000001];
        Arrays.fill(dp, -1);
        HashMap<Integer, Integer> count = new HashMap<Integer, Integer>();      
        long ans = 0;
        for (int i = 0; i < n; ++i) {           
            int d1 = f(seq[i]);         
            if (count.containsKey(d1)){             
                ans += count.get(d1);               
            }           
            Integer pres = count.get(d1);
            if (pres == null)
                count.put(d1, (count.containsKey(d1) ? count.get(d1) : 0) + 1);
            else
                count.put(d1, pres + 1);
        }
        out.println(ans);
        out.flush();
    }
}
