def f()
  a, b = gets.split
  ac, al, bc, bl = a.count("0"), a.gsub(/-/,"").size, b.count("0"), b.gsub(/-/,"").size
  a, b = a.to_i, b.to_i
  if ac == al - 1 && bc == bl - 1
    return (a*b)/10
  end
  c = a*b
  if c <  -99999999 || c > 99999999
    return "E"
  end
  return c
end

puts f()