#!/bin/python3
# John works at a clothing store. He has a large pile of socks that he must pair
# by color for sale. Given an array of integers representing the color of
# each sock, determine how many pairs of socks with matching colors there are.
#
# For example, there are n = 7 socks with colors ar = [1,2,1,2,1,3,2]. There is
# one pair of color 1 and one of color 2. There are three odd socks left, one of
#  each color. The number of pairs is 2.
#
# Function Description
#
# Complete the sockMerchant function in the editor below. It must return an
# integer representing the number of matching pairs of socks that are available.
# sockMerchant has the following parameter(s):
#
# n: the number of socks in the pile
# ar: the colors of each sock
# Input Format
#
# The first line contains an integer n, the number of socks represented in ar .
# The second line contains n space-separated integers describing the colors ar[i]
# of the socks in the pile.
# Sample Input
#
# 9
# 10 20 20 10 10 30 50 10 20
# Sample Output
#
# 3
import math
import os
import random
import re
import sys
from collections import Counter

def sockMerchant(n, ar):
    sum=0
    for values in Counter(ar).values():
        sum+=values//2
    return sum

if __name__ == '__main__':

    n = int(input())

    ar = list(map(int, input().rstrip().split()))

    result = sockMerchant(n, ar)

    print(str(result))

43b94b63f03078c074f273524d159c505ef8c664
<mask token>

<mask token>


def sockMerchant(n, ar):
    sum = 0
    for values in Counter(ar).values():
        sum += values // 2
    return sum


<mask token>

<mask token>


def sockMerchant(n, ar):
    sum = 0
    for values in Counter(ar).values():
        sum += values // 2
    return sum


if __name__ == '__main__':
    n = int(input())
    ar = list(map(int, input().rstrip().split()))
    result = sockMerchant(n, ar)
    print(str(result))

import math
import os
import random
import re
import sys
from collections import Counter


def sockMerchant(n, ar):
    sum = 0
    for values in Counter(ar).values():
        sum += values // 2
    return sum


if __name__ == '__main__':
    n = int(input())
    ar = list(map(int, input().rstrip().split()))
    result = sockMerchant(n, ar)
    print(str(result))

#!/bin/python3
# John works at a clothing store. He has a large pile of socks that he must pair
# by color for sale. Given an array of integers representing the color of
# each sock, determine how many pairs of socks with matching colors there are.
#
# For example, there are n = 7 socks with colors ar = [1,2,1,2,1,3,2]. There is
# one pair of color 1 and one of color 2. There are three odd socks left, one of
#  each color. The number of pairs is 2.
#
# Function Description
#
# Complete the sockMerchant function in the editor below. It must return an
# integer representing the number of matching pairs of socks that are available.
# sockMerchant has the following parameter(s):
#
# n: the number of socks in the pile
# ar: the colors of each sock
# Input Format
#
# The first line contains an integer n, the number of socks represented in ar .
# The second line contains n space-separated integers describing the colors ar[i]
# of the socks in the pile.
# Sample Input
#
# 9
# 10 20 20 10 10 30 50 10 20
# Sample Output
#
# 3
import math
import os
import random
import re
import sys
from collections import Counter

def sockMerchant(n, ar):
    sum=0
    for values in Counter(ar).values():
        sum+=values//2
    return sum

if __name__ == '__main__':

    n = int(input())

    ar = list(map(int, input().rstrip().split()))

    result = sockMerchant(n, ar)

    print(str(result))
