cc -O2 -pthread  -Wall -Wextra -Werror=implicit-function-declaration strings/ffsll.c -o strings/ffsll -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread -lrt  -lintl -lcrypt
strings/ffsll.c: In function 'main':
strings/ffsll.c:11:15: error: implicit declaration of function 'ffsll' [-Werror=implicit-function-declaration]
   11 |  int output = ffsll(input);
      |               ^~~~~
strings/ffsll.c:11:21: warning: 'ffsll' argument 1 type is 'long int' where 'long long int' is expected in a call to built-in function declared without prototype [-Wbuiltin-declaration-mismatch]
   11 |  int output = ffsll(input);
      |                     ^~~~~
<built-in>: note: built-in 'ffsll' declared here
cc1: some warnings being treated as errors