/in/foo.cc: In function 'int main()':
/in/foo.cc:13:15: warning: 'sum' may be used uninitialized [-Wmaybe-uninitialized]
   13 |         cout<<sum;
      |               ^~~
/in/foo.cc:5:17: note: 'sum' was declared here
    5 |         int n,a,sum,b,h;
      |                 ^~~