n = int(input())
H = []
for _ in range(n):
    L = list(map(int, input().split()))
    L.sort()
    H.append(L)
H.sort(key=lambda x: (x[0], x[1], x[2]))
DP = [0 for _ in range(n)]
DP[n - 1] = 1
for i in range(n - 2, -1, -1):
    res = 1
    xi, yi, zi = H[i]
    for j in range(i + 1, n):
        xj, yj, zj = H[j]
        if xi < xj and yi < yj and zi < zj:
            res = max(res, DP[j] + 1)
    DP[i] = res
print(max(DP))