A, B, C = gets.split.map(&:to_i)

need = A + B - C

#p need

wa = need.abs.to_s.each_char.map(&:to_i).sum

#p wa

if need > 0
  if A >= need + wa
    p wa
  else
    p A + 10*(need-A)
  end

elsif need > -7 && B > 0
  p 9 + need
else
  puts "Impossible"
end