lua, 112 bytes

Result

AC

Duration

716ms

Code [DL]

a=0
i=1
c={}
while a<117 do
s=io.read(1)i=i%51+1
c[i]=(c[i]or 0)|s:byte(1)a=c[i]|a&1
io.write(string.char(a))end

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                                 
       k!!!!!!!!u

stderr

strace