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