elixir, 258 bytes

Result

AC

Duration

1835ms

Code [DL]

defmodule F do
def f(s,t) do
  case IO.gets("") do
    :eof ->
      IO.write(String.slice(String.trim_trailing(t)<>String.duplicate("*",99),0,String.length(String.trim_trailing(s))))
    t ->
      IO.write(s)
      f(s,t)
  end
end
end
F.f(IO.gets(""),"")

stdin

               T                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
      K                                           

stdout

               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
               T                                  
      K*********

stderr

strace