/in/foo.c: In function 'main':
/in/foo.c:6:9: warning: zero-length gnu_printf format string [-Wformat-zero-length]
  printf("");
         ^~
/in/foo.c:7:10: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long int *' [-Wformat=]
  scanf("%d",&n);
          ^
/in/foo.c:14:11: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long int' [-Wformat=]
  printf("%d",s);
           ^