/in/foo.cc: In function 'int main()':
/in/foo.cc:7:2: error: 'cin' was not declared in this scope
  cin >> a >> b;
  ^
/in/foo.cc:8:51: error: 'cout' was not declared in this scope
  for (int j = a; j <= b; j++) if (hw(j) && ss(j)) cout << j << endl;
                                                   ^
/in/foo.cc:8:64: error: 'endl' was not declared in this scope
  for (int j = a; j <= b; j++) if (hw(j) && ss(j)) cout << j << endl;
                                                                ^
/in/foo.cc: In function 'int ss(int)':
/in/foo.cc:21:19: error: 'sqrt' was not declared in this scope
  for (; i <=sqrt(y); i++) if (y % i == 0) return 0;
                   ^