/in/foo.c: In function 'main':
/in/foo.c:27:11: error: 'i' undeclared (first use in this function)
   27 |     int n=i;
      |           ^
/in/foo.c:27:11: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:29:14: warning: format '%c' expects argument of type 'int', but argument 2 has type 'char *' [-Wformat=]
   29 |     printf("%c\n", a);
      |             ~^     ~
      |              |     |
      |              int   char *
      |             %s
/in/foo.c:27:9: warning: unused variable 'n' [-Wunused-variable]
   27 |     int n=i;
      |         ^