from collections import defaultdict
from functools import cmp_to_key
N = int( input() )
X = []
Y = []
Z = []
for i in range( N ):
  x, y, z = sorted( list( map( int, input().split() ) ) )
  X.append( x )
  Y.append( y )
  Z.append( z )
ord = sorted( list( i for i in range( N ) ), key = cmp_to_key( lambda x, y: 0 if X[ x ] == X[ y ] else ( X[ x ] - X[ y ] ) // abs( X[ x ] - X[ y ] ) ) )
dp = defaultdict( int )
for i in range( N ):
  best = 0
  for j in range( i ):
    a, b = ord[ i ], ord[ j ]
    if X[ b ] < X[ a ] and Y[ b ] < Y[ a ] and Z[ b ] < Z[ a ]:
      best = max( best, dp[ j ] )
  dp[ i ] = best + 1
ans = 0
for key in dp:
  ans = max( ans, dp[ key ] )
print( ans )