sed, 118 bytes

Result

AC

Duration

838ms

Code [DL]

1{
h
}
1!{
$!{
g
}
${
x;
:1
:2
/T /{s/T /T/;x;s/K /K/;x;}
t2
/ T/{
x;
/K /{
x;
s/ T/T/;
x;
s/K /KK/;
}
x;
}
t1;
x;
}
}

stdin

                        T                         
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
         K                                        

stdout

                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
                        T                         
         KKKKKKKKKKKKKKKK

stderr

strace