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