N = int(input())
A = []
for n in range(N):
	X,Y,Z = map(int,input().split())
	V = X*Y*Z
	A.append([X,Y,Z,V])
A.sort(key = lambda x: - x[3])
B = [[float("inf") for i in range(3)] + [0]]
for a in A:
	for b in B:
		P = [0] * 3
		for i in range(3):
			p = 0
			for j in range(3):
				if (b[j] > a[(j + i) % 3]):
					p = p + 1
			if p == 3:
				P[i] = 1
		if 1 in P:
			B.append(a[:-1] + [b[3] + 1])
			B.sort(key = lambda x: - x[3])
			break
print(B[0][3])