n=int(input())
b=[sorted(list(map(int,input().split()))) for i in range(n)]
e=[[] for i in range(n)]
d=[0]*n
for i in range(n):
  for j in range(n):
    if i!=j:
      if all(b[i][k]<b[j][k] for k in range(3)):
        e[i]+=[j]
        d[j]+=1
a=[1]*n
q=[i for i in range(n) if d[i]==0]
for s in q:
  for t in e[s]:
    d[t]-=1
    a[t]=max(a[t],a[s]+1)
    if d[t]==0:
      q+=[t]
print(max(a))