fortran, 203 bytes

Result

AC

Duration

728ms

Code [DL]

program x
character(len=50)::s
read(*,'(a)')s
print('(a)'),s
j=index(s,'T')
k=0
do while(k==0)
read(*, '(a)')s
s(j:j)='R'
k=index(s,'K')
if(k>0)forall(i=k:j)s(i:i)='R'
print('(a)'),s
end do
end program x

stdin

                                     T            
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                              K                   

stdout

                                     T            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                                     R            
                              RRRRRRRR            

stderr

strace