import sys
input = sys.stdin.readline

def ok(a, b):
    return a[0]<b[0] and a[1]<b[1] and a[2]<b[2]

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

for i in range(N):
    XYZ[i].sort()

XYZ.sort()
dp = [1]*N

for i in range(N):
    for j in range(i):
        if ok(XYZ[j], XYZ[i]):
            dp[i] = max(dp[i], dp[j]+1)

print(max(dp))