/in/foo.c: In function 'main':
/in/foo.c:13:9: warning: 'sum' may be used uninitialized [-Wmaybe-uninitialized]
   13 |         printf("%d",sum);
      |         ^~~~~~~~~~~~~~~~
/in/foo.c:4:17: note: 'sum' was declared here
    4 |         int n,i,sum;
      |                 ^~~