/in/foo.cc: In member function 'void PolyList::Add(PolyList)':
/in/foo.cc:79:14: error: 'L' was not declared in this scope
   for(Poly*p=L.Head; p!=NULL;p=p->next)
              ^
/in/foo.cc:82:29: warning: statement has no effect [-Wunused-value]
    newp->coef=p->coef;newp->index;
                       ~~~~~~^~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:97:5: error: request for member 'Add' in 'L1', which is of non-class type 'PolyList()'
  L1.Add(L2);
     ^~~
/in/foo.cc:98:5: error: request for member 'Output' in 'L1', which is of non-class type 'PolyList()'
  L1.Output();
     ^~~~~~