goruby, 43 bytes

Result

AC

Duration

855ms

Code [DL]

$_,*b,c=*$<;c[?K]*=99;s$_*-~b.sz,c[0..~/T/]

stdin

                   T                              
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                K                                 

stdout

                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                   T                              
                KKKK

stderr

<internal:golf_prelude>:4: warning: redefining Object#method_missing may cause infinite loop

strace