/in/foo.c: In function 'main':
/in/foo.c:12:9: warning: 'sum' may be used uninitialized [-Wmaybe-uninitialized]
   12 |         printf("%d",sum);
      |         ^~~~~~~~~~~~~~~~
/in/foo.c:4:15: note: 'sum' was declared here
    4 |         int n,sum;
      |               ^~~