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.
#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T ABS(T a) {
  return a > 0 ? a : -a;
}
template <typename T>
inline T MIN(T a, T b) {
  return a < b ? a : b;
}
template <typename T>
inline T MAX(T a, T b) {
  return a > b ? a : b;
}
template <typename T>
inline T CHKMIN(T &a, T b) {
  if (a > b) a = b;
  return a;
}
template <typename T>
inline T CHKMAX(T &a, T b) {
  if (a < b) a = b;
  return a;
}
template <typename T>
inline void SWAP(T &a, T &b) {
  static T c;
  c = a;
  a = b;
  b = c;
}
template <typename T, typename... T0>
T MAX(T a, T b, T0... c) {
  return a > b ? MAX(a, c...) : MAX(b, c...);
}
template <typename T, typename... T0>
T MIN(T a, T b, T0... c) {
  return a < b ? MIN(a, c...) : MIN(b, c...);
}
template <typename T, int n>
void myin(T a[]) {
  for (int i = (0); i < (int)(n); ++i) cin >> a[i];
}
template <typename T>
void myin(T &a) {
  cin >> a;
}
template <typename T>
void print(T a) {
  cout << a << ' ';
}
template <typename T, typename... T0>
void print(T a, T0... b) {
  print(a);
  print(b...);
}
template <typename T>
void println(T a) {
  cout << a << endl;
}
template <typename T, typename... T0>
void println(T a, T0... b) {
  print(a);
  println(b...);
}
int n, in[110000];
int mk[100];
int f(int x) {
  int ret = 0;
  while (x) {
    ++ret;
    x -= (x & -x);
  }
  return ret;
}
int main() {
  while (cin >> n) {
    memset(mk, 0, sizeof(mk));
    for (int i = (0); i < (int)(n); ++i) {
      cin >> in[i];
      ++mk[f(in[i])];
    }
    long long ans = 0;
    for (int i = (0); i < (int)(100); ++i) {
      if (mk[i] < 2) continue;
      long long tmp = mk[i];
      tmp *= (tmp - 1);
      tmp /= 2;
      ans += tmp;
    }
    println(ans);
  }
  return 0;
}
