import collections
N = int(input())
lsXYZ = [list(sorted(list(map(int,input().split())))) for i in range(N)]
lsXYZ.sort(reverse=True)
d = collections.defaultdict(lambda:0)

for i in range(N):
    x,y,z = lsXYZ[i]
    k = 1
    for key in d.keys():
        x1,y1,z1 = key
        if x1 > x and y1 > y and z1 >z:
            k = max(k,d[key]+1)
    d[(x,y,z)] = k

print(max(d.values()))