/in/foo.cc: In function 'int main()':
/in/foo.cc:12:17: warning: right operand of comma operator has no effect [-Wunused-value]
   12 |         cin>>l,r;
      |                 ^
/in/foo.cc:11:15: warning: 'r' may be used uninitialized [-Wmaybe-uninitialized]
   11 |         int l,r,sum;
      |               ^
/in/foo.cc:11:17: warning: 'sum' may be used uninitialized [-Wmaybe-uninitialized]
   11 |         int l,r,sum;
      |                 ^~~