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.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.StringTokenizer;

public class B {
    private static BufferedReader in;
    private static StringTokenizer st;
    private static PrintWriter out;
    
    public static void main(String[] args) throws IOException {
        in = new BufferedReader(new InputStreamReader(System.in));
        st = new StringTokenizer("");
        out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
        int n = nextInt();
        int f[] = new int[n];
        for (int i = 0; i < n; i++) {
            f[i] = f(nextInt()); 
        }
        Arrays.sort(f);
        int cnt = 1;
        long ans = 0;
        for (int i = 1; i < n; i++) {
            if(f[i-1]==f[i]){
                cnt++;
            }else{
                ans += (long) ((cnt-1) * cnt) / 2;
                cnt = 1;
            }
        }
        ans += (long) ((cnt-1) * cnt) / 2;
        System.out.println(ans);
    }
    private static int f(int x) {
        if(x==0)
            return 0;
        if(x==1)
            return 1;
        if(x % 2 == 1)
            return f(x / 2)+1;
        else
            return f(x / 2);
    }
    static String next() throws IOException{
        while(!st.hasMoreTokens()){
            st = new StringTokenizer(in.readLine());
        }
        return st.nextToken();
    }
    static int nextInt() throws NumberFormatException, IOException{
        return Integer.parseInt(next());
    }
    static long nextLong() throws NumberFormatException, IOException{
        return Long.parseLong(next());
    }
    
    static double nextDouble() throws NumberFormatException, IOException{
        return Double.parseDouble(next());
    }

}
