N = int( input() )
A = list( map( int, input().split() ) )

ans = - int( 1e30 )
def dfs( x, v, zero ):
  if x == N:
    global ans
    ans = max( ans, v )
    return
  if zero:
    dfs( x + 1, 0, zero )
  zero |= A[ x ] == 0
  best = max( v + abs( A[ x ] ), v * A[ x ] )
  if A[ x ] != 0:
    best = max( best, v // A[ x ] )
  dfs( x + 1, best, zero )
  best = min( v - abs( A[ x ] ), v * A[ x ] )
  if A[ x ] != 0:
    best = min( best, v // A[ x ] )
  dfs( x + 1, best, zero )
dfs( 1, A[ 0 ], A[ 0 ] == 0 )
print( ans )