n = int(input())
A = list(map(int, input().split()))
INF = float('inf')

def div(x, y):
    res = abs(x)//abs(y)
    if x*y < 0:
        return -res
    else:
        return res



M = A[0]
m = A[0]
for i in range(1, n):
    a = A[i]
    nM = -INF
    nm = INF
    if a != 0:
        nM = max([M+a, M-a, M*a, div(M, a), m+a, m-a, m*a,  div(m, a)])
        nm = min([M+a, M-a, M*a, div(M, a), m+a, m-a, m*a,  div(m, a)])
    else:
        nM = max([M+a, M-a, M*a, m+a, m-a, m*a])
        nm = min([M+a, M-a, M*a, m+a, m-a, m*a])
    M, m = nM, nm
print(M)