from itertools import *
from bisect import *
# from math import *
from collections import *
from heapq import *
from random import *
from decimal import *
import numpy as np
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def MI1(): return map(int1, sys.stdin.readline().split())
def MF(): return map(float, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LF(): return list(map(float, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
dij = [(0, 1), (1, 0), (0, -1), (-1, 0)]

def main():
    def div(a,b):
        res=abs(a)//abs(b)
        coff=(a*b>0)*2-1
        return coff*res
    n=II()
    aa=LI()
    now=set()
    now.add(aa[0])
    for a in aa[1:]:
        pp=set()
        mm=set()
        for s in now:
            ns=s+a
            if ns>=0:pp.add(ns)
            else:mm.add(ns)
            ns=s-a
            if ns>=0:pp.add(ns)
            else:mm.add(ns)
            ns=s*a
            if ns>=0:pp.add(ns)
            else:mm.add(ns)
            if a!=0:
                ns=div(s,a)
                if ns>=0:pp.add(ns)
                else:mm.add(ns)
        now=set()
        if pp:
            now.add(max(pp))
            now.add(min(pp))
        if mm:
            now.add(max(mm))
            now.add(min(mm))

    print(max(now))

main()