/in/foo.c: In function 'count':
/in/foo.c:5:10: warning: unused variable 'n' [-Wunused-variable]
  int i=0,n=0,sum=0;
          ^
/in/foo.c: In function 'main':
/in/foo.c:20:2: 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:21:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
  gets(b);
  ^~~~
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__;
              ^~~~
/tmp/cc7IdMyd.o: In function `main':
foo.c:(.text.startup+0x18): warning: the `gets' function is dangerous and should not be used.