#yuki_505

INF=float('inf')

def q(x,y):
 if x>=0:
  return x/y
 else:
  return -(abs(x)/y)

n=int(raw_input())
a=map(int,raw_input().split())
dp=[[-INF,INF] for j in xrange(n)]

dp[0][0]=dp[0][1]=a[0]
for i in xrange(1,n):
 for j in xrange(2):
  dp[i][0]=max(dp[i][0],dp[i-1][j]+a[i])
  dp[i][0]=max(dp[i][0],dp[i-1][j]-a[i])
  dp[i][0]=max(dp[i][0],dp[i-1][j]*a[i])
  if a[i]!=0:
   dp[i][0]=max(dp[i][0],q(dp[i-1][j],a[i]))

  dp[i][1]=min(dp[i][1],dp[i-1][j]+a[i])
  dp[i][1]=min(dp[i][1],dp[i-1][j]-a[i])
  dp[i][1]=min(dp[i][1],dp[i-1][j]*a[i])
  if a[i]!=0:
   dp[i][1]=min(dp[i][1],q(dp[i-1][j],a[i]))

print dp[n-1][0]