labyrinth.lab

 )::}_101-@     Increment the counter, leave a copy on aux, check if we're below 101, otherwise terminate.
 "       {      This leaves a negative number on main.
 "       :
 "       }_5%122:_117_66      If 5 divides the counter push "Buzz" in reverse order.
 "          "          "
 "          """"";{"""""
 "                :
 "                }_3%122:_105_70      If 3 divides the counter push "Fizz" in reverse order.
 "                   "          "
 "                   """"""1_""""
 "                        ;
""""""""""""""""""""""\!{;``{       If the negative number was still on top, just print the counter.
;                           ;       Otherwise, we found at least one of the two divisors and print
\""""""""""""""""""""""""""""       everything until we hit the negative number (which we discard).
 ."