from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

N = int(input())
XYZ = []
for _ in range(N):
    X = list(map(int,input().split()))
    X.sort()
    XYZ.append(tuple(X))
    
ind = [0]*N
e = [[] for _ in range(N)]
for i in range(N):
    xi,yi,zi = XYZ[i]
    for j in range(N):
        xj,yj,zj = XYZ[j]
        if (xi<xj)&(yi<yj)&(zi<zj):
            e[i].append(j)
            ind[j] += 1

v = deque()
val = [0]*N
for i in range(N):
    if ind[i]==0:
        v.append(i)
        val[i] = 1

while v:
    
    x = v.popleft()
    
    for ix in e[x]:
        
        val[ix] = max(val[x] + 1,val[ix])
        ind[ix] -= 1
        if ind[ix]==0:
            v.append(ix)
print(max(val))