N=int(input()) S=input() S=S.rstrip().split(" ") list1=[] for i in range(N): list1.append(int(S[i])) #print(list1) ans=list1[0] for j in range(1,N): list2=[ans+list1[j],ans-list1[j],ans*list1[j]] ans=max(list2) print(ans)