Dima got into number sequences. Now he's got sequence *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub>, 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* &lt; *j* ≤ *n*) are there, such that *f*(*a*<sub class="lower-index">*i*</sub>) = *f*(*a*<sub class="lower-index">*j*</sub>). Help him, count the number of such pairs.
The first line contains integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">5</sup>). The second line contains *n* positive integers *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub> (1 ≤ *a*<sub class="lower-index">*i*</sub> ≤ 10<sup class="upper-index">9</sup>).

The numbers in the lines are separated by single spaces.
n = int(input())

a = list(map(int, input().split()))

def f(x):
    cnt = 0
    while True:
        if x == 1:
            cnt += 1
            break
        elif x % 2 == 1:
            cnt += 1
            x = (x-1)/2
        else:
            x = x/2
    return cnt

my_dict = {}

for i in range(n):
    d = f(a[i])
    if d in my_dict.keys():
        my_dict[d] += 1
    else:
        my_dict[d] = 1



result = 0
for key in my_dict.keys():
    t = my_dict[key]
    result += int(t*(t-1)/2)

print(result)