c-gcc, 121 bytes

Result

WA

Duration

636ms

Code [DL]

main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}

stdin

x8u9g4e5z7r9m6d2d2i5j8b8y3g5l4qj6q5w3f3in9h5f9oc5b7n5dy7x3h9a5i3p4o7k4m8u2bc3s7d7vtxss5t8h9

stdout

stderr

/tmp/code.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
 ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:36: warning: implicit declaration of function 'gets' [-Wimplicit-function-declaration]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                    ^~~~
/tmp/code.c:1:88: warning: comparison of constant '9' with boolean expression is always true [-Wbool-compare]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                        ^~
/tmp/code.c:1:76: warning: comparisons like 'X<=Y<=Z' do not have their mathematical meaning [-Wparentheses]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                           ~^~~~~~~~~~~~
/tmp/code.c:1:92: warning: the omitted middle operand in ?: will always be 'true', suggest explicit middle operand [-Wparentheses]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                            ^
/tmp/code.c:1:101: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                                     ^~~~~~
/tmp/code.c:1:101: warning: incompatible implicit declaration of built-in function 'printf'
/tmp/code.c:1:101: note: include '<stdio.h>' or provide a declaration of 'printf'
+#include <stdio.h>
 main(){char i[101];int b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                                     ^~~~~~
Segmentation fault (core dumped)

strace