import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)

N = int(input())
box = []
for _ in range(N):
    a, b, c = sorted(map(int, input().split()))
    box.append((a, b, c))
box.sort()

cnt = [1] * N
for i in reversed(range(N)):
    a, b, c = box[i]
    for j in range(i + 1, N):
        p, q, r = box[j]
        if a < p and b < q and c < r:
            cnt[i] = max(cnt[i], cnt[j] + 1)

print(max(cnt))