aa, bb, cc, dd = gets.split.map(&:to_i)

if dd >= 10
  puts "Impossible"
  exit
end

score = 0

100.times do |i|
  r = 0

  b = [bb, 100 - r].min
  bb -= b
  r += b
  score += 2.pow(i) * b * 50

  a = [aa, 100 - r].min
  aa -= a
  score += 2.pow(i) * a * 100
end

puts "Possible"
puts score