View Compilation Error

0_0_35420894_12361.cpp: In function 'int main()':
0_0_35420894_12361.cpp:12:8: error: 'cin' was not declared in this scope
  while(cin>>hex>>a>>b)
        ^
0_0_35420894_12361.cpp:12:13: error: 'hex' was not declared in this scope
  while(cin>>hex>>a>>b)
             ^
0_0_35420894_12361.cpp:16:4: error: 'cout' was not declared in this scope
    cout<<"-"<<hex<<uppercase<<-sum<<endl;
    ^
0_0_35420894_12361.cpp:16:20: error: 'uppercase' was not declared in this scope
    cout<<"-"<<hex<<uppercase<<-sum<<endl;
                    ^
0_0_35420894_12361.cpp:16:37: error: 'endl' was not declared in this scope
    cout<<"-"<<hex<<uppercase<<-sum<<endl;
                                     ^
0_0_35420894_12361.cpp:18:4: error: 'cout' was not declared in this scope
    cout<<hex<<uppercase<<sum<<endl;
    ^
0_0_35420894_12361.cpp:18:15: error: 'uppercase' was not declared in this scope
    cout<<hex<<uppercase<<sum<<endl;
               ^
0_0_35420894_12361.cpp:18:31: error: 'endl' was not declared in this scope
    cout<<hex<<uppercase<<sum<<endl;
                               ^