bash-busybox, 44 bytes

Result

AC

Duration

1371ms

Code [DL]

sed '1h
${:1
x
s/ $//
t1
x
s/K /KK/
t1
h}
g'

stdin

                                    T             
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                K                 

stdout

                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                    T             
                                KKKKK

stderr

strace