def read_data():
    N = int(input())
    xyz = []
    for _ in range(N):
        x, y, z = map(int, input().split())
        xyz.append((x, y, z))
        xyz.append((x, z, y))
        xyz.append((y, x, z))
        xyz.append((y, z, x))
        xyz.append((z, x, y))
        xyz.append((z, y, x))
    return N, xyz

def solve(N, xyz):
    xyz.append((0, 0, 0))
    xyz.sort()
    dp = [0] * (N * 6 + 1)
    for idx, (x, y, z) in enumerate(xyz):
        tmp = 0
        for idx2 in range(idx):
            xx, yy, zz = xyz[idx2]
            if xx < x and yy < y and zz < z:
                if tmp < dp[idx2]:
                    tmp = dp[idx2]
        dp[idx] = tmp + 1
    return max(dp) - 1

N, xyz = read_data()
print(solve(N, xyz))