#yuki_497

n=int(raw_input())
l=[]
for i in xrange(n):
 temp=map(int,raw_input().split())
 l.append(sorted(temp,reverse=True))
l=sorted(l)
res=[1 for i in xrange(n)]
for i in xrange(n):
 for j in xrange(i):
  if l[i][0]>l[j][0] and l[i][1]>l[j][1] and l[i][2]>l[j][2]:
   res[i]=max(res[i],res[j]+1)
print max(res)