n = gets.to_i
a = gets.split.map(&:to_i)
x = a[0]
y = a[0]
1.upto(n - 1) do |i|
    b = [x * a[i], x + a[i], x - a[i], y * a[i], y + a[i], y - a[i]]
    tmp, tmp2 = b.minmax
    x = tmp2
    y = tmp
end
p x