/in/foo.c: In function 'main':
/in/foo.c:7:20: warning: 'i' is used uninitialized [-Wuninitialized]
    7 |         for(int i;i<=n;i++)
      |                   ~^~~
/in/foo.c:7:17: note: 'i' was declared here
    7 |         for(int i;i<=n;i++)
      |                 ^