n=int(input())
a=list(map(int,input().split()))

dp=[[a[0],a[0]] for i in range(n)]

for i in range(n-1):
    t=[]
    t.append(dp[i][0] - a[i+1])
    t.append(dp[i][1] - a[i+1])
    t.append(dp[i][0] + a[i+1])
    t.append(dp[i][1] + a[i+1])
    t.append(dp[i][0] * a[i+1])
    t.append(dp[i][1] * a[i+1])
    if a[i+1] !=0:
        t.append(-(-dp[i][0] // a[i+1]))
        t.append(-(-dp[i][1] // a[i+1]))
    t.sort()
    dp[i+1][0]=t[0]
    dp[i+1][1]=t[-1]

print(dp[-1][1])