View Compilation Error

0_0_37517316_9416.cpp: In function 'int main()':
0_0_37517316_9416.cpp:12:5: error: 'cout' was not declared in this scope
     cout << hanot(n) << endl;
     ^
0_0_37517316_9416.cpp:12:25: error: 'endl' was not declared in this scope
     cout << hanot(n) << endl;
                         ^