n = int(input())
a = list(map(int,input().split()))
if n % 2 == 1:
    if n == 1:
        print(a[0])
    else:
        print(1)
else:
    a.sort(reverse=True)
    m1 = a.pop()
    m2 = a.pop()
    a.append(m1*m2)
    a.sort()
    print(a[0])