java, 170 bytes

Result

AC

Duration

1842ms

Code [DL]

class A{public static void main(String[]a)throws Exception{int d=1,c;while((c=System.in.read())>0){if(c>83)d=0;d-=c%2*51;System.out.print(d<1?"A":(char)c+"");d=++d%51;}}}

stdin

                                                 T
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
              K                                   

stdout

                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
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                                                 A
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                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
                                                 A
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                                                 A
                                                 A
                                                 A
              AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

stderr

strace