View Compilation Error

0_0_37675187_28709.cpp: In function 'void update_seg(int, int, int, const int&, const int&)':
0_0_37675187_28709.cpp:76:3: error: 'cout' was not declared in this scope
   cout << "sum = " << sum[root] << endl;
   ^
0_0_37675187_28709.cpp:76:36: error: 'endl' was not declared in this scope
   cout << "sum = " << sum[root] << endl;
                                    ^