a, b, c = gets.split.map(&:to_i)

ans = 10**9
(0..a).each do |i|
  (0..b).each do |j|
    s = i + 10*j
    (1..s).each do |k|
      t = s - k
      if (t%10)+(t/10) + (a-i) + (b-j) == c
        ans = [ans, k].min
      end
    end
  end
end
if ans == 10**9
  puts "Impossible"
else
  puts ans
end