# coding:utf-8

import sys

n = int(input())
item = sys.stdin.read().splitlines()
item_listA = []
item_listB = []
for i in item:
    item_listA.append(list(map(int, i.split(' '))))
for i in range(n):
    for j in range(3):
        item_listB.append(item_listA[i][j])
item_listB.sort()

lvup_count = 0
for i in range(len(item_listB)):
    if item_listB[i] != 0 and item_listB.count(item_listB[i]) >= 2:
        lvup_count += 1
        item_listB[i:i+2] = [0,0]
    else:
        continue

lvup_count += (len(item_listB) - item_listB.count(0)) // 4

print(lvup_count)