def aa(m):
    dp2[0]=min(dp2[0],m)
    dp2[1]=max(dp2[1],m)

n=int(input())
s=1
for i in list(map(int,input().split())):
    if s:
        s=0;
        dp=[i,i]
        continue
    dp2=[1<<60,-1<<60]
    for j in dp:
        aa(j-i);aa(i+j);aa(i*j)
        if i:
            aa(j//i)
    dp=dp2
print(dp[1])