N = int(input())
a = list(map(int, input().split()))
dp1 = [0] * N
dp1[0] = a[0]
dp2 = [0] * N
dp2[0] = a[0]

for i in range(1, N):
    dp1[i] = max(dp1[i-1]+a[i], dp1[i-1]-a[i], dp1[i-1]*a[i], dp2[i-1]*a[i])
    dp2[i] = min(dp2[i-1]+a[i], dp2[i-1]-a[i], dp2[i-1]*a[i], dp1[i-1]*a[i])

print(dp1[-1])