View Compilation Error

0_0_22659031_23273.cpp: In function 'int main()':
0_0_22659031_23273.cpp:8:2: error: 'string' was not declared in this scope
  string n;
  ^
0_0_22659031_23273.cpp:11:3: error: 'cin' was not declared in this scope
   cin >> n;
   ^
0_0_22659031_23273.cpp:11:10: error: 'n' was not declared in this scope
   cin >> n;
          ^
0_0_22659031_23273.cpp:22:3: error: 'cout' was not declared in this scope
   cout << (root == 0 ? 9 : root) << endl;
   ^
0_0_22659031_23273.cpp:22:37: error: 'endl' was not declared in this scope
   cout << (root == 0 ? 9 : root) << endl;
                                     ^