N=int(input())
B=[list(map(int,input().split())) for i in range(N)]

E=[[] for i in range(N)]
E_INV=[[] for i in range(N)]

D=[0]*N

for i in range(N):
    X=sorted(B[i])
    for j in range(N):
        Y=sorted(B[j])

        if Y[0]<X[0] and Y[1]<X[1] and Y[2]<X[2]:
            E[i].append(j)
            E_INV[j].append(i)

            D[i]+=1

Q=[]
DP=[1]*N

for i in range(N):
    if D[i]==0:
        Q.append(i)

while Q:
    x=Q.pop()

    for to in E_INV[x]:
        DP[to]=max(DP[to],DP[x]+1)
        D[to]-=1

        if D[to]==0:
            Q.append(to)


print(max(DP))