/in/foo.c: In function 'main':
/in/foo.c:7:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     while (gets(s))
     ^~~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.c:9:13: warning: unused variable 'lens' [-Wunused-variable]
         int lens=strlen(s),lena;
             ^~~~
/tmp/ccP8D1eA.o: In function `main':
foo.c:(.text.startup+0x2f): warning: the `gets' function is dangerous and should not be used.