from itertools import product

N = input()
A = map(int, raw_input().split())
ans = float('-inf')

for c in product('+-*/', repeat=N-1):
    a = A[0]
    for i in xrange(N-1):
        if c[i] == '+':
            a = a + A[i+1]
        elif c[i] == '-':
            a = a - A[i+1]
        elif c[i] == '*':
            a = a * A[i+1]
        elif c[i] == '/':
            a = a + A[i+1]
    ans = max(ans, a)
print ans