c-gcc, 77 bytes

Result

WA

Duration

979ms

Code [DL]

b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}

stdin

          T                                       
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
      K                                           

stdout

          c                                       

stderr

/tmp/code.c:1:1: warning: data definition has no type or storage class
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
 ^
/tmp/code.c:1:1: warning: type defaults to 'int' in declaration of 'b' [-Wimplicit-int]
/tmp/code.c:1:3: warning: type defaults to 'int' in declaration of 'c' [-Wimplicit-int]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
   ^
/tmp/code.c:1:5: warning: return type defaults to 'int' [-Wimplicit-int]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
     ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:5: warning: type of 'd' defaults to 'int' [-Wimplicit-int]
/tmp/code.c:1:20: warning: implicit declaration of function 'getchar' [-Wimplicit-function-declaration]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                    ^~~~~~~
/tmp/code.c:1:20: note: 'getchar' is defined in header '<stdio.h>'; did you forget to '#include <stdio.h>'?
+#include <stdio.h>
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                    ^~~~~~~
/tmp/code.c:1:18: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                  ^
/tmp/code.c:1:48: warning: implicit declaration of function 'putchar' [-Wimplicit-function-declaration]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                                                ^~~~~~~
/tmp/code.c:1:56: warning: suggest parentheses around operand of '!' or change '|' to '||' or '!' to '~' [-Wparentheses]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                                                        ^~
/tmp/code.c:1:70: warning: suggest parentheses around arithmetic in operand of '|' [-Wparentheses]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                                                                     ~^~
/tmp/code.c:1:32: warning: operation on 'd' may be undefined [-Wsequence-point]
 b,c;main(d){for(;c=getchar();)d=85%~c?++d%51:0,putchar(!d|b?99:c),b=c&1|b*d;}
                               ~^~~~~~~~~~~~~~~
Arithmetic exception (core dumped)

strace