import math
import sys
def S(): return sys.stdin.readline().rstrip()
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())

n = I()
item = {}
for _ in range(n):
    a, b, c = MI()
    if a not in item:
        item[a] = 1
    else:
        item[a] += 1
    if b not in item:
        item[b] = 1
    else:
        item[b] += 1
    if c not in item:
        item[c] = 1
    else:
        item[c] += 1
ans = 0
for k, v in item.items():
    if v > 1:
        ans += v//2
        item[k] = v % 2

sum_v = 0
for v in item.values():
    sum_v += v

ans += sum_v // 4
print(ans)