/in/foo.c: In function 'main':
/in/foo.c:8:5: warning: 'gets' is deprecated [-Wdeprecated-declarations]
     gets(a);
     ^~~~
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:65:10: warning: passing argument 1 of 'printf' makes pointer from integer without a cast [-Wint-conversion]
   printf(' ');
          ^~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:364:12: note: expected 'const char * restrict' but argument is of type 'int'
 extern int printf (const char *__restrict __format, ...);
            ^~~~~~
/tmp/ccwG7jTj.o: In function `main':
foo.c:(.text.startup+0x2f): warning: the `gets' function is dangerous and should not be used.