import sys
from itertools import product

input=sys.stdin.readline
N=int(input())

K=6
P=[0]*(2**K)

for i in range(N):
    S=list(map(int,input().split()))

    for E in range(2**K):
        F=E
        p=1
        for k in range(K):
            if E&1==1:
                p*=S[k]
            E>>=1

        P[F]=max(P[F],p)

X=0
for A in product(range(4),repeat=K):
    B=[0,0,0,0]
    for k in range(K):
        B[A[k]]|=1<<k

    X=max(X,P[B[0]]*P[B[1]]*P[B[2]]*P[B[3]])

print(X)