import sequtils
template times*(n:int,body) = (for _ in 0..<n: body)


proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  var minus = false
  block:
    let k = getchar_unlocked()
    if k == '-' : minus = true
    else: result = 10 * result + k.ord - '0'.ord
  while true:
    let k = getchar_unlocked()
    if k < '0' or k > '9': break
    result = 10 * result + k.ord - '0'.ord
  if minus: result *= -1

let n = scan()
var ansMin = 0
var ansMax = 0
n.times:
  let x = scan()
  var plus = ansMax + x.abs()
  var minus = ansMin - x.abs()
  var mult1 = ansMax * x
  var mult2 = ansMin * x
  ansMin = min([plus,minus,mult1,mult2])
  ansMax = max([plus,minus,mult1,mult2])
echo ansMax