27(2)

#https://inf-ege.sdamgia.ru/problem?id=27891
data = open('27.txt').readlines()
n = int(data[0])
x = list(map(int, data[1:]))
a, b, c, d = 0, 0, 0, 0 #a - 14, b - люб, с - 2, d - 7
answ = 0
for e in x:
    if e % 14 == 0:
        answ = max(answ, e * b)
    answ = max(answ, e * a)
    if e % 2 == 0:
        answ = max(answ, e * d)
    if e % 7 == 0:
        answ = max(answ, e * c)

    if e % 14 == 0:
        a = max(a, e)
    b = max(b, e)
    if e % 2 == 0:
        c = max(c, e)
    if e % 7 == 0:
        d = max(d, e)
print(answ)