View Compilation Error

0_0_30162910_23453.cpp: In function 'int main()':
0_0_30162910_23453.cpp:7:2: error: 'cin' was not declared in this scope
  cin>>n;
  ^
0_0_30162910_23453.cpp:11:3: error: 'cout' was not declared in this scope
   cout<<hex<<x;
   ^
0_0_30162910_23453.cpp:11:9: error: 'hex' was not declared in this scope
   cout<<hex<<x;
         ^
0_0_30162910_23453.cpp:12:9: error: 'endl' was not declared in this scope
   cout<<endl;
         ^