/in/foo.cc: In function 'int main()':
/in/foo.cc:8:10: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>a,b;
          ^
/in/foo.cc:9:15: warning: 'b' is used uninitialized in this function [-Wuninitialized]
     cout << a+b << endl;
               ^