N = int(input())
a = [int(i) for i in input().split()]
def dfs(n):
	if n == 0:
		return a[n]
	res = dfs(n-1)
	ret = -10**17
	ret = max(ret,res + a[n])
	ret = max(ret,res - a[n])
	ret = max(ret,res * a[n])
	if a[n] != 0:
		ret = max(ret,res // a[n])
	return ret
print(dfs(N-1))